im about to start swimming, and im trying to lose weight, practice is about 2 hours long, i weigh about 150ish.
do you think that swimming 5 times a week will help me lose weight?

Swimming 5 times a week should, so long as you don't goof off or do very little swimming each day. Try to push yourself as best you can, and make sure you don't overeat either.
A simple rule: Burn more calories than you take in, and you lose weight. But yeah, 5 times a week should be good. Maybe try fitting in a bit of other exercise when you can