Hello dear,
Your are in 8th and start planning about your goal ,,,,,,its appreciable😊👌👍.
You r in 8 th grade ,,,means going to enter in 9th grade ….so you can start your neet prep because 9th and 11th and 10 and 12 are linked,in fact 9th and 10th are basics of 11th and 12th respectively.
And if you start your prep now your basics will be cleared well.
So ,,,,go ahead.
All the best.