We are in semi-similar boats good sir. I just did my first regional a few weeks ago, and the numero uno piece of advice I can give you is have fun. Bowl, enjoy the challenge, and make the most of your time bowling. Keeping a level head will help you play your game easier and with less doubts.
Now, onto the good stuff. Bring EVERY piece of gear, you'll never know what you'll need. Don't hesitate on adjustments, trust yourself and go at it. The ball will tell you everything you'll need to know about the conditions. I found that the practice session was very helpful, and gave me a good idea of what to expect on Saturday. Saturday played a bit tighter, but I knew where to start from AND how and how quickly the lanes will break down (carry down first, then they opened up, then had to move in, etc etc).
The courtesy in the tournament is very very awesome - it took me a bit to get used to, but once I got it I was all about it. Don't let it get into your head that it's worlds different, because it's not at all, it's just a LOT smoother than what you're used to in league.
The usuals there were more than willing to help me out with things I didn't quite understand (writing down what gear you used, etc) and they made me feel rather comfortable. After all, it's just bowling, ya know?
Make sure your equipment is all legal (static weights, etc.) and that if you use a bionic wrist that it's allowed in PBA competition. I had to get a new bionic wrist because the one I had was NOT allowed in PBA tournaments.
And again, just have fun man. I hope you have a blast and bowl well!
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Proud Supporter of Rob Stone
Obviously, you aren't a golfer.
Some stayed in the foothills, some washed logs like teeth.