Start up disk is full

[brasky654]

Hi, I have a Macbook pro that is having issues and any help/advice would be greatly appreciated. I had been getting a message that my start up disk was almost full, then a few days a go programs like I tunes and Word were not working. I restarted my computer only to find that it would not start properly, I got a message that my start up disk is full and a blue screen appeared. Now when I start it all that appears is a blue screen. What can I do to get my computer working properly again?
Thanks in advance

 

[simsaladimbamba]

Have you tried any of these steps?

Mac doesn't boot
Resolve startup issues and perform disk maintenance with Disk Utility and fsck
Troubleshooting: My computer won't turn on​