Think I've been really dumb

Told a person online we could collaborate using Go to my assist.com. Couldn't establish a connection and then they told me they'd be back. In the meantime I'm now wondering if im an idiot and
they could've accessed my info, etc. what can I do to safe guard myself now?!

Couldnt log on, had to download java...twice.

300 people have viewed this and no one can tell me how to make my computer safe? Maybe I was not clear.

Do I restart router?

If he could access one computer could he access all our computers in our home?

Thanks, I am just paranoid then? Relief