Looking back, I feel like I worded this badly. You’ll probably be fine just reading normally though. If you don’t understand something try parsing it, looking up unknown words/grammar, rereading it, etc. I generally wouldn’t worry about perfection or going as far checking a grammar guide most of the time. You won’t get a lot done.
Anyway, for more concrete advice, using a dictionary is pretty much a must. I recommend reading something that you can use the Rikaisama extension with. It makes parsing sentences and looking up unknown words/grammar much easier. The usual recommendation is visual novels, but they’re not for everyone. Otherwise you’re probably reading some form of web content. Web novels might be a decent alternative. For reading visual novels see this link (https://www.reddit.com/r/visualnovels/wiki/vnhooking).*
*I believe Rikaisama is supposed to become unsupported soon, in which case you’ll have to use Rikaichan or something instead. Also this might not work for Steam visual novels. Not sure.
For N5/N4 grammar I went through Genki I and II while reading. Since then I’ve mostly just used Jisho’s definitions for grammar. As long as you’ve got the basics down, I think it’s pretty easy to just throw any grammar you come across in Anki. Reading provides plenty of natural example sentences.