How to keep your child occupied

What are some things to do to keep my child mentally stimulated? My husband and I decided to not send her to pre-k for different reasons so she will be home with me all day while dad works. Normally we watch a movie, she has learning workbooks, we play. Is that okay to continue? I was going to start taking her to the park to play but it just gets so hot and I’m pregnant so it’s hard for me to deal with the heat. Thank you!