Of course it's OK, everybody starts somewhere!
Quantizing is simply placing notes directly on the beat you specify, in the event that you played them erratically. For instance, you could set your score to quantize 1/4 note beats on the double bass staff. Well, you can hit record and start hammering away at notes randomly with really bad timing, and Notion (or any other software that quantizes) will place those notes perfectly on the 1/4 note beat. It has advantages and disadvantages. The advantage is that your notes will be perfectly on the beat. The bad new is, your notes will be perfectly on the beat, lol. It can make this sound sterile, so often DAW's and I assume scoring tools like Notion will have a human feel option the slightly adjust notes randomly by a few milliseconds, still keeping them on the beat but adding the human variation element. Another use of quantizing is to play your notes in perfectly on the beat and then setting quantizing to make it a swing feel, things like that. So it can correct and enhance.
Hope all that makes sense!