See https://www.firesafemarin.org/contractors for a list of contractors who’ve completed basic training in wildfire preparedness. Any licensed tree company or arborist should do fine for tree removals. We don’t typically recommend specific contractors, and have had good experiences with nearly every tree service you’ll find in the “yellow pages” or Google. Ensure that they are a local, licensed contractor, and carry insurance.
Grass cutting can be accomplished by most tree services also, however a landscaping service is fine, too. Be sure they carry insurance. Grass cutting should be done with string trimmers, and should occur only in morning hours, and never on a “Red Flag Warning” day.