Learning a language is made of bursts of progress, which are exhilarating. But let's face it: also many plateau, which can last for months. It can be demotivating to not see progress for a while.
Here's how I've visualized my progress in Indonesian over time, to quantify learning:
I found a list online of the top 2000 Indonesian words. Now if I were to do it again, I'd probably do it differently: I'd pull content that matches my target learning tone. For me, that's casual Indonesian, so I'd pull up text from books written by an author I like, all the blog posts from a blog I like, etc. If you're looking for professional though, you could pull up business news articles, or presentation transcripts.
Then, list the words in a Google sheet, and test yourself on those words every year, count a 1 for words you know, 0 for those you don't, and track your score. Over years, it really helps.