@Shanny8 has solid advice!
I'd actually suggest lower on the print end, though. If you can find a place that only does 5-10 copies of each design, that's a better start, just to see if they'll move at all. You more than likely won't sell more than that on one design in a weekend. I'd only consider going higher to like 20 if it was THE NEW HOT THING and I cornered the market sooner than most.
Even my most popular prints, I've never sold more than 20 in a weekend, and that one was thanks to randomly hitting on nostalgia at the right time (it was a Sesshomaru print, lol).
The only other thing I'll mention is that sometimes, event size doesn't scale with sales, especially if you're a newbie with not a lot of inventory. When I was just starting out by selling issue 1, our first con was awesome! it had 5k attendees and I sold a lot of copies. Blew my expectations out of the water.
Next con was a little larger at 7k. I sold a little over half of what I did at the first con, so it was eh... and then we went to the biggest con in the midwest, and they had 30k. I thought we'd hit a bigger market for sure!
Nope. A fourth of the original total sold. It was pretty demoralizing, and it is our worst con to date.
Here is the reasoning behind that, though:
1st con - Local to me, so a lot of people knew me or saw my flyers around town marketing it. The venue was small and the artist alley could only fit so many people, so there was low competition. This event continues to bring in 3x the revenue of other conventions for me for this exact reason.
2nd con - Mid size con so there's less competition, but I didn't have the local clout. I was a nobody and people were seeing me for the first time. Tbh this is most events and I came to expect this as my average.
3rd con - I was completely drowned out. The vendor hall was massive, and I simply couldn't compete with the veterans in the hall who had nicer displays and more importantly, a wide variety of product to offer. I had maybe 5 prints, 8 buttons, and one comic issue at this time. While that was totally fine for a beginner, it wasn't enough to make it profitable. Only now--5 years later--am I confident enough to try to get into bigger cons again.
So basically, I'd suggest going to events that are maybe 2-10k to get the most bang for your buck. Smaller events are fine too, just don't expect as many sales.
And your art is good, dude, don't worry about it so much ^^ I think you could do well if you carved out a good niche for yourself!
(I've edited out my numbers so people don't compare themselves to me, but if you'd really like to know more concrete data feel free to PM me)