Stop editing.Can some1 help me with1solution? I explainedProblms

I have got a second-hand old acer netbook with linux. I deleted stuff, installed others, I have got a warning message about space. I have uninstalled more stuff from ubuntu center, and the ubuntu center disappeared. It was working fine, I was downloading files and didn't get that warning message again. I disabled updates.
After some months I had to shut-down. Then I have got a message about low graphic mode. I cannot open folders or setting, looked like loading and nothing appeared. Searching on internet they said it was about video driver, I wanted to update it but 'cannot update' .
I have read on internet how to delete programs using the terminal, and I have deleted what I installed and wanted to update it, again "please free MB" .
I also wanted to install a video driver using the terminal, and now I cannot open the linux, I just get white text on black screen.
And now I cannot open the linux where all the applications and folders are. I find only tutorials about how to install "windows" opening applications. And no, I don't have that USB stick and I cannot get one.
I don't know what to do with it. I learned how to install and use windows on a computer. On a computer with windows is easy, I have a system restore option. But with linux, I don't know what to do. The only USB stuff I have is a music player, and was detected as music device when I connected it, and now looks like "not booting" .
CAN SOMEONE HELP ME ?? i DON'T KNOW WHAT TO DO TO MAKE IT WORK AGAIN. STOP EDITING MY QUESTIONS, I EXPLAINED THE PROBLEMS I HAD WITH IT, AND NOW I CANNOT OPEN THE OPERATING SYSTEM, I SEE JUST WHITE TEXT ON BLACK SCREEN, I DON'T KNOW WHAT TO DO TO MAKE IT WORK AGAIN.