lljk I'm jealous, we go to the naze at least once a month and I've never found any fossils or sharks teeth down there!
op a lot is going to depend on what you like to do on holiday tbh.
Nice walks in the countryside? Probably not. Nice walks along beaches? Lots of lovely ones between Walton and Clacton Pier, especially Holland Haven which has a lovely nature reserve too, or The Naze at Walton.
Days at the beach you want Walton or Frinton (hiring a beach hut is a stellar idea too!) or if you have to go to Clacton you want to go towards martello tower.
Clacton Pier is the only decent attraction for an older child that we have, and from outside the pier you can get a 'train' to Holland and back again which is a novelty.
Waltons pier is apparently really good these days but I haven't been in years.
Jaywick really is not a good place, "Jaywick Village" or "jaywick sands" are rebranding attempts, just don't go there. It has been on a lot of the benefits TV shows (and had a few specifically about it) I think because it is a massive culture shock, the main area is mostly these little shacks that were only ever designed to be temporary holiday homes but have become permanent accommodation.