As little pressure as necessary is the way to go.
As for strings, 9s are a common gauge, sort of all purpose lead and rhythm. Heavier strings are preferred by many people for rhythm work, but they are also more difficult to play and can be harder on the fingers. I would get used to the lighter gauge first and then try heavier ones. It's up to you, but ultimately you should experiment with different brands and gauges to find what works best for you.
You are at GuitarMasterClass.net
Don't miss today's
free lick. Plus all our lessons are packed with
free content!