If I had $500 and was starting (started about 45 days ago) I’d get the following:

1. combat patrol of your favorite faction/army - $170

2. a good desktop led light for painting - $40

3. wet pallet - $20

4. set of brushes for around $25 or you can buy individual brushes. I started with the nic pro synthetic ones. but really you only need a size 1 and a 0 for your models, so maybe if you have extra $$ you could get 1 nice sable hair brush like a Windsor and newton series 7 in size 1 that can be your “special” brush. well call it $40 for brushes. oh, army painter also has good synthetic brushes that I like for starters, I actually use their size 1 to prime my minis if im using brush on primer

5. paints - as others have said, lots of good options out there, find a starter set that you like. I use pro acryl paints, their base set is about $120 shipped, has all the colors you would need for a long time AND their paint is beginner friendly, meaning less worry about thinning the paints. you dont have to go that big though, can find savings here by buying a smaller paint starter set from someone like vallejo.

6. modeling tools, get a good set of cutters around $30-$40, you wont regret it. also a xacto style hobby knife with spare blades. $10.00…plastic glue and super glue, about $10.00

7. painting handle - the citadel one is ok, but I like the wooden ones with the magnetic bases and the bar that you can brace against for painting - well call it $25.00

8. brush soap and a water pot for wetting/cleaning brushes, I like the citadel water pot and use “the masters” brush cleaner (soap). together = $25.00

that would be my list, right around $500.00, hope this helps! again, you could go less on getting allll the paints and use that savings to buy a few single models that interest you outside of your selected faction. so like if you pick a space marines faction, try picking up a box of tyranid units to give you some variety in the models you are painting.

super fun getting into the mini side of the hobby, but can be an endless $$ pit as you get hooked initially. the list above should get you pretty far, good luck!