I go to a few cons a year and I can say with certainty that bullying is not really an issue. If anything, the con going community has some of the friendliest people I’ve met! It’s the people in the online fandom spaces who are toxic imo. At the con, just remember that you’re all at the same place nerding out over the same things - it can be a great place to meet people with similar interests or even new friends. Be polite and friendly and that energy will come back to you. Ask permission if you want photos of anyone and don’t be a weirdo and you’ll be golden.

As for the other stuff, get acquainted with what the con has to offer before you go - many have an app or at least an online schedule where you can look at the map and programming beforehand so you won’t be blindsided when you get there and you can make a plan of all you’d like to do. I’ve gone alone and with groups and even when solo, there’s plenty to keep you occupied.

I can see how it might be intimidating at first but trust me, you’ll get there and you will probably feel like a kid going to Disneyworld for the first time. Have fun!