If you just want a girlfriend to stop your friend's thinking you are gay then this isn't really fair, you could find end up hurting someone if you are just using her.
However if you do actually want a girlfriend for other reason's then you should remember that look's aren't everything.
You may see yourself as ugly but to someone else you could seem attractive, some people's beauty come's from inside!
I agree with skyep that starting friendships first is a good idea, also making a girl laugh can see her becoming attracted to you.
Try not to look too hard, just wait for it to happen in it's own time!!
Good Luck xx