Replying to Features to create a unique back yard park set up

Any ideas on features to put into a backyard that are quick and easy . I read some past threads on backyard set ups but lack some of the tools for a proper build. I have a hand saw, hammer and old wood... that is about all the tools that are at my disposal. I tried to make a rail out of pvc and it is janky as fuck. It is very unstable and with a lot of weight wobbles a lot. I also have an old skate rail that scratches my bases and is slow. Any suggestions.

I go to college in sunny CA  and dont have any access to snow.

Getting ready for the season and need to take let lose