Excellent question! Fist of all take the opportunity to play against the higher tiers, whether stroke or AS play. Hopefully you will find a player that encourages rather than discourages you, like a coach and HAS not forgotten what it was like to climb the the tiers. Usually you will know the "attitude" of those who you will be playing with/against, if they fit your style, don't be shy to friend them!
Practice, practice get familiar with your equipment and remember the "process" should be fun, winning is a bonus
Additionally, many quality people are out there to enjoy, unfortunately there are a few "spoiled" ones as well! Take the encouragement and toss the pettifogs!