FishAngular12

Hi, out of college (CS Degree) I got a job at a large software company, utilizing a proprietary (and primitive/simplistic) language, which I've held for the past 8+ years. This language also doesn't seem to have a modern-day standard counterpart. I am getting bored of it technologically speaking, and would like to have the opportunity to have a development job elsewhere in the country.

How bad is it to those who are hiring that this is my only development experience? If I were to learn a new framework such as React or Angular, would I essentially be starting back at square one (in terms of Junior Software Developer role)? Would my prior experience be basically meaningless?