The issue is whether the produce you’re procuring seed from is a hybrid or not. If it’s not, you should be good to go with seed saving. If it is a hybrid, the results will be unpredictable, although not necessarily bad. This is an interesting read on the topic: https://www.motherearthnews.com/organic-gardening/save-hybrid-seeds-zbcz1602/

I think I know what tomato product you’re referring to, and I think you’d really like a lot of the heirloom cherry tomato varieties out there, which are even tastier. They’re very common in almost any seed catalogue nowadays (so many varieties it’s overwhelming!), but if you want to sample them first, I’d recommend stopping by a farmers market next summer. Be sure to chat with the seller to find out if they’re hybrids or not; larger farms will probably have hired help selling the products so you may not get a good answer, but if the seller is the farmer themself, they’ll absolutely know whether the tomatoes they’re selling are hybrids or not. I also would recommend either the seed catalogue or farmers market routes because that way you’ll be able to match the tomato variety to your growing conditions; a tomato variety bred for hydroponic growing for instance may not do well in soil. Also there are two types of tomatoes, determinate and indeterminate, which have slightly different care and harvest requirements. In short, you’re better off knowing what variety of tomato you’re growing so you can research care and growing conditions, vs growing seeds from an unknown tomato variety where you have to wing it and hope for the best.