You'll get as much instruction as you need. Seriously.
Also, one of the ways you learn is to be corrected when you are deficient. Seriously. Also, NAPSters and prior enlisted will have a lot of good tips that they'll share with others. Some is "instruction" but most is figuring it out as you go along.
Inspections are important at USNA but one of the things you learn is to balance your time, especially when you need to balance inspections vs. other things, such as academics. For example, during PS, inspections are important because you don't have a lot else to do (well, you do, but it's of equal importance). During Ac Year, inspections become somewhat less important; the best looking room and uniform in the brigade won't help you if you're failing your classes.
As for changing uniforms, during PS you do something called "uniform races." In all honesty, it's one of the single most important things I took away from USNA in terms of "plebe stuff." Holds you in very good stead the rest of your life.