As many as you feel comfortable with. That can be 10, that can be 100 or really any other number. There is no right or wrong. If you are the type that is fine throwing tons of different grammar points at yourself and get them to stick quickly there is no limit. If you are new to all the grammar points you are learning, in general not that familiar with Japanese yet or lack time / the ability to handle more than a few points at once go with a low number.
In the end this is a question that can be answered differently for anyone.
But ye, if you are learning/encountering those points for the very first time then its probably never a bad idea to take it at a slower little-by-little pace.
Learning Japanese is not like English and is definitely a marathon if anything - its easy to start counting “today I did X of N4 so I will be done with N4 by XYZ and done with N3 by XYZ” - matter of fact is you wont. Either you really stick with it but have a very rough grasp on those grammar points till you got lots of immersion or you are a linguistic genius that doesnt need immersion or you might already have had lots of exposure to those points before… or you notice a while in how often you get stuff wrong and that grammar doesn’t work the same as vocab does.
Either way, have fun with your studies