Having your own tomatoes is great, they are so much better flavour and sweetness.
We have a greenhouse, so we just pick tomatoes when they are ripe. Previously we have picks some when they are still green, and keep them (remove the stalks, as they tend to go mouldy soon in the house) in a plastic container. They can still ripen, without sunshine, in a couple of weeks. Though it is ideally to keep them on the vine in plenty sun.
Strangely, our tomatoes haven’t had that much sun in the last few weeks, but they are very sweet tasting - and I have no idea why!