I am in total agreement with everything @davidechols said above.
I have more laps that anyone should have. You’ll soon learn how each of your laps cut, which will change over time as the lap becomes more worn. For example I have an old 600# that cuts like an 800#, etc.
Regarding Toppers… With a good master lap, a quality topper will perform as well as a solid lap.
As David eluded to above, “breaking in” a new lap (solid or topper) is critical. I just use a junky piece of corrundum to knock off the higher pieces of diamond. Once the new disk is cutting a smooth surface, you are good to go. Another easy way to break in a new disk is to use it for preforming a piece of rough especially if the material is say quartz.
Meet points? A decent 10x loupe is good enough for judging, so it’s good enough for me. Practice makes “perfect”. However, as a beginner remember that the quality/accuracy of your crown meets (for example) is directly related to how well you’ve done the meets in pavilion. I’ll also often leave a row of meets a little short, as pre-polish/polishing will “bring them in”. It just takes a lot of practice.