Buying Membership For The First Time, What Should I Do?

The title says it all. I'm buying membership for the first time and I'm not sure what the first steps are that I should take in progressing further. Right now, all of my F2P stats are in the 30s or 40s, and my combat stats are all 45, including range and magic. The only exception is that I only have 22 prayer. Also, all F2P quests are complete. Thank you in advance!