You can use dplyr::left_join, dplyr::right_join, etc. But R does work differently than SQL. I use both SQL & R a lot. I would recommend installing MySQL on your computer and loading some tables to play with. You can use MySQL Workbench. It's all free.
SQL as a language is fairly straight-forward. The challenge is thinking in set-based terms and avoiding things like cursors. There are tutorials with SQL problems that will help you sharpen your SQL thinking skills too.
I would also recommend pulling data from MySQL to R to get better at what SQL should handle and what R should handle regarding datasets.