My first advice, if you're planning to homeschool, is just to stop thinking about stuff as "school stuff" and definitely stop talking about it as such.
It sounds like you do a lot of great stuff with your son! There is absolutely no reason a wiggly kid needs to sit still to benefit from a read-aloud-- let him bounce, roll, flip, zoom around the room, to his heart's content. Or play with legos, puzzles, or tiles while you read. Or pick books that encourage movement. There is a great list here, along with suggested activities that kids might like. (If your son doesn't, no problem, he's not in a classroom, so you can find your own.)
Nursery rhymes, too, are fantastic if you want to incorporate movement and literacy (and, often, numeracy).
With fine motor skill development, if he's not interested, he's not interested, but...what happens if you get a couple of pairs of scissors, glue sticks, and a stack of magazines, say nothing to him, and just sit at the table and enjoy yourself cutting and making a collage? Or if you get a bunch of tissue paper and just sit there tearing it up and pasting it onto paper? Or put on some music and color or draw by yourself? What if you spend 30 minutes a day at the table doing one of those things and not even trying to convince him to join you, but just enjoying yourself?
To me, this is something kids sometimes get in preschool-- they try out activities they might not otherwise because the other kids make them look fun and enjoyable and interesting. Having an only child is hard. If he doesn't have an opportunity to watch older kids do a lot of these things, you're kind of responsible for making the activities seem desirable enough to try.
Math is everywhere for a wiggly kid. Go on shape hunts. Count everything. Estimate together how many Cheerios in his bowl, m&ms in the package, height of a tree (how many mommies tall?), etc. See what he's paying attention to and help him verbalize it-- patterns, addition and subtraction, etc. Make number lines and have him figure out how many different ways he can hop to 5 or 6. Sort stuff.
I think a prepackaged curriculum would be a bust for this kid. Your intuition and sense of creativity will help you figure out what he needs! But one word on that: your pediatrician should be your close ally. Keep an eye on the things that concern her. They don't have to concern you, but if he is doing things noticeably differently or on a different timeline than other kids his age, that's valuable to know and reflect on. I am a little inclined to defensiveness on this point, but it's part of the pediatricians job to keep track of kids' development. She can't judge a kid based upon his behavior during one office visit, but she can share her opinions about what you should expect so you can think about whether it's something to consider. (I remember eye contact being something my ped. also looks for at the 4 year visit, and something my kids just couldn't do with her. But after she talked to me about it, I made it a point to be sure I was making frequent eye contact with my children. I should have been doing it anyway, but that was helpful to me to have reinforced at the visit.)