For dance class, hungup is right. Find some adult jazz classes, which will teach you basic technique without you being with 10-year-olds, and they're usually scheduled later in the evening to allow for working peeps.
I disagree on the acting classes though.
Start with some basic community theater and get a feel for it. You for sure don't need acting classes to be in a community theater production, which will also have rehearsals in the evenings. In fact, it's better to do community theater for free and decide if it's something you like before investing the money into acting classes, which I'd only do if I wanted to make it a career.
I've been doing theater since I was 10, and have been in 30 productions, currently doing professional (non-equity), and have never taken an acting class, but I would definitely go through some paid workshops if I decided to go equity (the stage actor's union).
Hope that helps! Break a leg!!!