Welcome to the Forum!
You'll likely get as many answers as there are Forum members, because everyone has their favorite ammo. However, you're off to a good start with your choice of Gold Dots as self-defense ammo. They have a very good reputation within the shooting and law enforcement communities, so you're good to go there. My only recommendation is that you shoot at least 100 of them to make sure they are totally reliable in your Shield. If all 100 load, fire, and eject without a problem, you're all set. If you have problems, you may need to look at other brands of self-defense ammo, but I believe that's unlikely.
My Shield 9 has nearly 6,000 rounds through it, and my favorite range ammo is Winchester NATO 124 grain. I've found it to be the most accurate of any of the brands of ammo I've shot from my Shield, and (in normal times) it's affordable, typically selling for $9-$10 for a box of 50. Unfortunately, these days it's double that price, which is awful. Blazer Brass is usually affordable (I haven't checked lately), and it's OK ammo, so it may have to do for now.
If your local range is well run, they should have ammo to buy for those who come to shoot there. It may be expensive, but at least you'll get to practice, and practice you must. A lot. If you have a friend who knows how to shoot, bring him or her along and have them give you some guidance. If not, take lessons at the range. Every range I know offers them.
As to cleaning, I clean my guns after every use.
I'm sure some of my Forum colleagues will be along soon to give you the benefit of their experiences. Their firmly held opinions may differ from mine, but of course, mine are right.
Good Luck!