seriously, make the lip on pretty small, if you get into the habit of relying on big jumps then its hard to break. just be confident, and remember that you can still bail on cement and be fine, so you probably aren't going to kill yourself if you fall once. Also, if you've been doing rails for two years, you should be totally ready, last year was my first ever in the park and i've done some decent urbans this year without any problems.