Create a small program, and iterate, iterate, iterate.

I took the entire pandemic off from programming, and when I had to go back to find a job, I needed to level up quickly to be able to pass programming interviews.

I wrote a program to start downloading stock quotes, then added writing to a database, then added code to graph it with flask, etc. If you choose something you're interested in and keep expanding the scope of the project, it's the best way to learn.

And functionally, Python 3 isn't a huge difference over Python 2, especially if you're starting from scratch again. For me the biggest change is adding parentheses around my print statements. Everything else is pretty similar.