How familiar are you with vim? You've been using it with vscode for a while so I figure you're somewhat familiar with vim shortcuts? If you haven't already, you should run through vimtutor. The built in help is very good in vim, it's good to develop a habit of using :help and :helpgrep before googling. When in help pages you can use C-] to go to references in the documentation.
Some resources that I found useful when getting in to vim:
Articles: Oil and vinegar, Death by a thousand files
Talks: Let vim do the typing, How to do 90% of what plugins do with just vim
Speaking of plugins, tpope has an excellent repo of very good plugins that feel like they fit in very naturally with vim. I can especially recommend fugitive, commentary and surround