Welcome to High School ball in Utah!
There are several Utah officials that peruse this board. I'm a member of the Provo association, and if I mispeak about the details of another association, they'll surely correct me.
Along the Wasatch front there are three associations: North (Odgen area north to Logan), Salt Lake and Provo (covers Lehi south to Juab, east to Tabiona). You'll be expected to join one of these associations. There are a few other associations in the state, but you stated Wasatch Front, so I'll confine my answer to that area.
For sub-varsity ball, each of these associations has a single assigner for all of the high schools and jr. high schools in the area. There is a separate assigner for varsity along the Wasatch Front (actually Logan to nearly Richfield, I think).
If you've registered with the UHSAA, which I assume you've done, you'll get a packet in the mail in the coming months. It'll have info about association meetings: time, location, etc. There are generally a couple each month throughout the season. You'll be expected to attend.
In Provo there will be an additional meeting or two for new officials. I believe Salt Lake has a class for first and second year officials (even if you've been doing this for a while, you'll generally be classed as a first year offical once you start doing high school ball). Ogden may have similar arrangements.
As your first step, you'll want to contact your association president and introduce yourself. He can answer specific questions about his association. The UHSAA can help you with those names and numbers, or you can email me through the board and I'll help you with them.
You'll need to get seen and evaluated by members of the board for your association. Your president can help you with the details of how his assocation handles that. Once you've been seen, you'll be ranked and that will improve the quantity/quality of assignments you get.
As far as I can tell, assignments work pretty much the same all along the Wasatch Front. We assign using The Arbiter, so you'll get your assignments online. Generally speaking, they assign based on ranking and location plus availability. You might not get a lot of games assigned your first year, but if you're available for turn-backs, and keep in touch with the assigner, you can pick up quite a few games that way.
Provo also assigns some rec leagues. I don't know about the other associations. Those games are less popular and so there's a good opportunity to score some games there.
So, as far as how to approach the president to get games, you obviously want to make a good impression, but there's a pretty good mechanism in place for assigning and you don't need to come to him with your hat in your hands or anything like that.
As far as avoiding the pitfalls, I have but one suggestion. It sounds like you've got some good experience. That's great. School ball is a little different: a little more formal and a little more serious. You're expected to have better mechanics, better game control, better everything than you would in a rec league.
So despite how good you think you are (and we all think we're pretty good or we'd have given it up long ago
), be humble and approach this new adventure with an attitude of wanting to learn from everybody. Ask your partners and the officials who come early for the next game for feedback. Watch the varsity folks work. Go to whatever clinics or classes are offered and listen. Be willing to consider what others tell you, even if you think it's wrong or stupid or picky. You don't have to implement it, but listen and consider and try it before you discard it.
Be eager, available, teachable and you'll do just fine.
Oh, and have fun