If you come from Windows Mint is an excellent starting point. People shit on it because it doesn’t have all the fancy bells and whistles you get with more latest releases, but on the flip side it’s super reliable and as a new user that reliability is worth more than all the bells and whistles.
Even dimensional analysis works best with metric because sometimes you need to convert units and almost all conversion in metric are base 10, so something like 1kg/km is 1000g/1000m is 1 gram per meter. But in imperial 1 pound/mile is 16 ounces / 5280 feet is who the fuck knows how many ounces per feet.