Just started, need some help.

This is the first golf game I've played in a long time. I made my own guy but can I level him up outside of pro career? I don't like only playing like 4 holes at a time in pro career I want to play full founds and level up. I could use any other tips you think would be useful. My main problem is all these different clubs. Different irons and woods? Different degrees? What's the difference?