Do a package. It will take the stress out of it, if you’re not used to booking holidays, especially with kids!
Jet 2, tui, or easyjet holidays are all good.
We’ve done a whole mix of packages from AI to self catering.
I’d recommend fuertaventura. Lots of lovely beaches and hotels, short transfer to most of the resorts, and pretty chilled vibe. It’s never as busy as Tenerife or Lanzarote.
We visit the canaries once a year,- without kids now, and like all of them.
I’d also look at menorca. Really good for children.