are there any full lists of all the commands for all languages?

Answer 1

There is a glossary of things taught here. goto lessons select language click the dots next to the language then glossary

Answer 2

No, Sololearn doesn't currently have a list of commands. However, there are cheat sheets for most languages easily found on the web. Also see here:

https://www.sololearn.com/Discuss/643767/cheat-sheets

Answer 3

Also, in trending there is this:

https://www.sololearn.com/Discuss/510275/ultimate-pdf-collection-for-learn-programming