where can I rent an indoor playground and toys for a 3 year old?
Not sure what you mean by indoor play ground? Is it a ball pit or slides? I dont know about toy rental but look for a store called Once Upon a Child which sells gently used toys (and may buy them back when you are done). There are several locations in Orlando. https://www.onceuponachildorlandofl.com/
I don't in what area you are staying and if you have a car. If so, it would be quite easy to take the kid to the park.
Go to Goodwill buy what you need then donate back when you leave.