I highly recommend the “Human Japanese” apps for your study, they do a great job of explaining various grammar points, with lots of example sentences, all with audio, and a breakdown of the sentences as well.
Start with Beginner and then once you are finished that you can get Intermediate.
Reading is also a really great study tool once you have a base level, and for that you can check out Satori Reader (Same people as Human Japanese) there is a fair amount of conent there that is available for free, with audio to go with the reading so you can listen along.
I would also suggest checking out the NHK Easy news website - NEWS WEB EASY
They have news articles written in simple Japanese with Furigana.
And don’t forget Tadoku Graded readers as well, free online books for various levels of Japanese - Free books – にほんごたどく