So much of basic skateboarding is just building confidence on flat ground. It's hard to hurt yourself when you're like 2 inches off the ground, at worst I've gotten some scraped knees and palms.
This guy's videos are down to earth if you want some quick motivation:
Also it might look goofy, but just get some basic knee and elbow protectors and a decent helmet. Those are the only areas you easily hurt as long as you are on flat ground with no obstacles.