What can I expect at my first fest?

You are definitely going to want to bring your own toiletries. They stock the portos' but I wouldn't trust the toilet paper to be there or to be clean.

There are plenty of porto potties depending on the time of day. You won't have to wait longer than a few minutes though, at the worst time. I believe showers are $10, though I haven't used them. At roo they were cold water only. There are faucets you can use to rinse off if you would rather do that (that is what I do).

I wouldn't worry about the people, sure if you leave out something nice it could go missing but that is the extent of bad things happening. I have never seen a fight (or worse) in the 7 festivals ive been too. That includes Roo which has a much worse crowd than the previous two lockn's. I won't tell you that drugs aren't there, all I can say is if you don't want to do them then don't do them.

there are dozens of posts from before last year's fest with great advice, including in the ultimate fest list.

Sort it out for personal preference and the things that are important to you, or which would bother you, v. things that others don't care about (like using a portapotty).

Some people like to bring all their food and set up elaborate cook stations; some just eat at the vendors--and their food was very good, and also reasonable. That's just an example of how you have to sort through the advice for what works for you.

And the weather is a huge factor--are you from nearby or familiar?--it can range from hot and muggy to cold and damp; hard rain or bone dry, and everything in between. And over four days, maybe all of it.

oh man, i'm so excited for you! i just started fests a few years ago and i'm HOOKED. there is absolutely nothing to be freaked out about. there will be a ton of people, but really it's one big family. there will be some illegal substances there, can't avoid it. that being said, don't ever feel any pressure to do anything you aren't comfortable with. i regularly turn down things i just don't care to participate in because that's not how i enjoy my festivals. if you do, do your thing! vendors are awesome people; walk around and talk to them. they're almost always friendly. car camping is a good way to start. good for locking up valuables, charging your phone (just be careful of battery usage), and the occasional A/C break if it gets really hot. 
here are some tips to make it awesome:

1. have an open mind. you'll probably see some weird shit. embrace it. you'll regret it if you don't
2. meet as many people as you can, especially your neighbors. we're all in it together.
3. don't be afraid to ask for help. people at fests are super friendly and will almost always jump at the chance to help others
4. forget the outside world exists. forget twitter, instagram facebook, your friends, your family (maybe check in once or twice a day.) get lost in what is happening in the moment and forget that it will ever end and the real world awaits your return.
5. take all the pictures you want of new friends and cool strangers, but be careful not to experience the fest (especially the music) through a tiny little screen. there will be plenty of pictures, video, and audio available after the fest, and probably of a much higher quality than what you will record.
6. "dance like nobody is looking." i know that's a corny saying, but it's true. don't get hung up on anyone else's insecurities. boogey your ass off.
7. hydrate. hydrate. hydrate.
8. bring a backpack for swag, a blanket, TP (or wet wipes, gotta take care of your bum), flashlight, glowsticks, sunscreen, etc. whatever you feel like you'll need to be comfortable. 
9. pace yourself. it's a marathon, not a sprint. if you go crazy the first night, you'll be playing catch up all weekend.
10. all that being said, shit happens. there will always be a few rotten apples that are out looking to take advantage of people. not trying to scare you, just be smart. don't bring anything with you that isn't replaceable and lock up valuables in your car (out of plain sight).
11. always make lists with an odd number of points to drive the OCD crowd bonkers

hope these help! welcome to the board! hang out for a while and you'll meet some great people and pick up a lot of great pointers.

For what its worth, this is my 1st as well. I've found the folks on this board to be friendly and informative and if its any indication of the people I'm going to meet at the event, it should be really special.

Oh my very informative, thank u so much for the advice. Glad to hear and see that there are friendly people. Do hope to meet new people well hope I can be open and be able to talk to new people instead being shy.

Prepare to get grossed out by the portos late night. They can get pretty nasty. Def bring extra tp.

If you are going to pay for a shower take it in the evening when it is not Too hot out. I walked out last year and was instantly sweaty, will not nake that mistake again.

Dont worry about drugs, its not nearly as bad as roo or other fests i have been to. If its something you dont like to participate in dont. Nobody will force anything on you.

btw welcome to the community

Well hey thanx for the welcome, and then for the insight,
I probably will take plenty of wet wipes and sanitizer. And most likely do my own showers
Ya iv hurred alot about the drugs, its all fine with me

oh ya! thank you waycha!

12. attend the lockn forum meetup / craft beer exchange. it was killer last year and i hope it's even better this year!
also, anti-monkey butt products are amazing! the big towels are really great for giving yourself a little cleanup if you dont want to spend a small fortune on showers, like me

new map isn't out yet and they may move things around. I drove by there yesterday; nothing is set anywhere.

the line-up and band schedule is on the official website; there may be more bands, re-arranging or cancelling.

Expect the unexpected...

We have been pretty lucky the last two years with weather. Based on the past 25 years camping at the nascar race the same weekend, plan for rain. Pray it does not come, but have mud boots and rain gear just in case. I always pack my camp stuff in Plastic totes to keep things dry. Like many have said above, keep and open mind and have fun. Lockn 2013 was my first festival. Some of the people I have met have become like family.  Don't worry about the drug stuff.  Due to my job at the local school system, I cannot touch anything.   I have had not issues at all.