Speaking from experience (and also as a fairly good skiier turned snowboarder)... take a lesson so that you can get the proper form. The most valuable thing I learned during that time is to keep your knees bent, lean forward slightly and keep your hands more or less still at your belt buckle. Once you feel comfortable, get good at turns by really leaning into them and committing your body weight to the turn. If it’s not icy, your edge will keep you dug in.
Also, you’ll want to be deliberate about your time on catwalks, which will totally burn out one side of your legs if you travel in one direction too long. It’s just painful after a while, mainly.
As far as where to go, I’m only familiar with ski areas in NM and CO, so I don’t know if that helps. You’ll want to go somewhere, though with powder/packed powder conditions, a good bunny hill, and ideally that offers wide open green and blue runs that don’t flatten out to the point where you’d have to skate on skis, since you’ll have to dismount and walk or push like a skateboard. You also don’t want moguls.
Packed powder is okay, it’s just that you fall harder on a snowboard, and the run won’t be as forgiving when you turn. Powder is better for later in your trip, once you’re comfortable with some speed and getting into turns. Also on powder, you’ll want to lean back (i.e. uphill) to keep your nose up.
A day on the bunny hill, though, is invaluable, because you’ll get a great opportunity to practice your form while turning, plus you’ll have to buckle and unbuckle multiple times and mount and dismount the lift a number of times. After two seasons, I still fall more often than not getting off the lift.
Also, if you can, go with other snowboarders rather than skiiers. Snowboarding, especially at a beginner level, requires different terrain and rhythms during a run than skiing.
As far as cost goes, stick to the criteria above and go with whatever’s within your budget. I would reiterate that with a group, it’s more fun to snowboard with snowboarders and ski with skiiers. I think each has it’s merits and that it’s possible to enjoy both, although I personally want tougher terrain when I ski and cruising, open terrain when I snowboard.
Lastly, have a great time. I may get on the slopes this weekend, and I’m stoked!