Grammar guide!

For free there is About – Learn Japanese that’s quite well liked. https://www.youtube.com/@organicjapanesewithcuredol49 is liked by some as well.

Payed resources you can look at the usual books (Minna no Nihongo, Japanese from Zero, Genki, etc.) or online resources like Bunpro, Imabi etc.

Have a look through the ultimate resource list, I’m sure you’ll find something you like: The Ultimate Additional Japanese Resources List!