Loads of great advice here. I’m pretty closely aligned with @brookter.
I’ll add a couple of things to the mix:
Read your dialogue aloud. Doing so makes it clear what is and isn’t needed. If you’re new to this, then perhaps have someone else read it to you. As a writer, you have to develop writing and reading personas who are prepared to argue with one another. It takes a while.
Don’t worry about dialogue “tags” when writing a first draft. The following is adequate:
A: There’s someone at the door.
B: Who is it?
A: Maybe we should open it and find out.
Suddenly, the door burst open.
B: It’s a man with a gun!
For A and B, use character initials.
I’m also not a fan of Strunk and White. I prefer to live by Garner’s, which is huge (as it must be), UK/US bilingual, not very expensive, and a thing of beauty. There are no rules, of course; but when I need to be consistent, Garner’s is a worthy bible.
Of the rest, I enjoyed the recent Dreyer’s English. It pads itself with a part deux entitled, The Stuff in (sic) the Back; but, if you ignore that, it dispenses copious amounts of sound and practical guidance.