Start up disc almost full, yet I have 168gb on other stuff. Help!!!

I have a Late 2008 Macbook, which should have 250gb of space. Operating system OsX 10.9.5, I can't upload the most recent version as I dont have enough space. I have been cleaning up, deleting pics, music and I just downloaded ccleaner to de-frag.

I have 168.31 gb of Other stuff and I have no idea what it could be. I have some uni documents from old days but I am thinking that it is mostly rubbish left over.

Please help me to clean up. What can I get rid of?

I have tried to book a genius appt but they are never available and I have a child so cant just go into the shop and wait hours to be seen... I am so frustrated that I have pics on camera and phone etc that I can't look at, or update or do anything as everything is running slowly so am giving up!

All advice appreciated!!

Thanks