I’ve heard mixed opinions about duolingo, people say that LingoDeer is better but I haven’t used either so you’d have to ask around. Then there’s also BunPro for grammar only, but that seems to be more of a complementary resource than a main source of grammar. I haven’t used this one either.
If you prefer videos to walls of text then CureDolly is highly recommended, but you would have to get used to the unique style of her videos. I’ve watched one or two of her videos and they seem fine.
You can see other recommendations in this thread. Try them out and see which ones work best.