My wife and kids are leaving for three weeks in Europe tomorrow evening just as the berries, tomatoes, and peppers begin to ripen. I don't know anything about sauce or jam making.
I don't know much either, but for the berries, worst case just freeze them individually on a baking sheet as they ripen, then transfer frozen berries to a ziploc bag or other airtight container. You can make jam later or throw them in smoothies or just enjoy them as a summer snack.
Dehydrator? You can preserve tomatoes by cutting them in half, laying on baking trays and throwing some thyme sprigs, olive oil, salt and smashed garlic cloves over them. Bake at like 200F for as long as it takes to dry them out.