Can someone please give me a rundown of what I need to have and do for my cats?

I was given 2 cats and also fell pregnant (unexpectedly) soon after, it’s a bit chaotic and I’m exhausted. I want to make sure I have everything and am doing all I can to make them happy! I’ve looked online but I also want advice/tips from people.
They’re both vaccinated and desexed, one has gingivitis but has been cleared for feline aids - apparently that’s a symptom of aids according to a vet I saw?? It doesn’t seem to be getting better though.
I keep them inside as much as I can but one is an escape artist who runs out as soon as I open the door.

Some additional questions..
How often should I see a vet for general check ups?
Any tips on teeth and gum care?
Should I clip their nails if they go outdoors?
Approximately many scratching posts/trees should I have?
I have two large litter boxes that I clean out daily and change the litter weekly, is that enough?

Please don’t judge me, I just feel overwhelmed but I know I can make probably do more.