Went to FurDU, one of the biggest conventions in Australia, second only to confurgence, but most people I've talked to say FurDU is better
Here is my advice on how to have the most fun at a con
1. Know someone there and get their number. Several times during a con you may not know where any of your friends are and you might not know what to do. Being able to text your friends and ask what they're up to can help you significantly in these situations and will make sure you're in a constant bout of fun!
I cannot stress how important it is, cause otherwise you may feel overwhelmed or lonely 2. Don't be shy to meet new people! See someone with a cool fursuit or someone relaxing, talk to them! Furry conventions are as much about meeting new people as they are about meeting old friends, just say hi, get their online details and have a blast.
3. The best fun in furry conventions isn't necessarily the convention itself! Try to get invited to a room party or something, they can be a huge blast and you can get up to all sorts of crazy shenanigans. That's not to say you should AVOID the main furry activities, by all means you should attend any events that interest you! But just remember that sometimes the best fun happens behind the scenes.
4. Don't forget to sleep, drink and eat healthy once and a while! You can get sick in cons really quickly and trust me, by the second or third day you'll feel exhausted, so don't over work yourself, drink plenty of water and try to get at least six hours of sleep a night!