If you're losing more than you win, it's best to just have a team that you play 10 games a week for points, until you get some gear. And try to play at offpeak or wierd hours as you'll have a better chance of going up against scrub teams (in my experience anyhow).

If you want to play more than 10 games per week to work on tactics then consider having 2 teams, one to practice on that you don't care about the ranking, and another that you earn points from.

Might consider 3v3 with your friend for points as well, 1 healer + 2 dps is pretty strong there. You can put 6 people on a 3v3 team so just rotate shaman to get your games played in.