It's too early for tomatoes to go outside. It needs to be 10 degrees pretty much round the clock.
What to do with them in the meantime depends on how big they are now. Can you post a picture?
If they are 5-10 cm tall and have a few pairs of leaves, and/or they have roots showing at the bottom of the pot, you should pot them up in a pot a bit bigger (and a lot deeper) than the pot they're in now. Get a bag of multipurpose compost to use for this. Knock the current pot firmly on the base and/or squeeze it gently. Then hold the plant by a leaf and lift the pot off the whole thing. Put the plant into the new pot so that it's sitting on the bottom. Surround with fresh compost, taking off any leaves that would be under the compost but leaving at least one pair. Water gently and put on a warm sunny windowsill or in a light porch. The plant will grow extra roots from the submerged stem which will make it much stronger.
If the weather takes ages to warm up you can do this two or three times. Mine are currently in their 3rd pots.
Ultimately you will need a pot the size of a supermarket flower bucket for each plant. Or you could use grow bags, though these are harder to manage.
I don't know so much about strawberries but I think they'll be fine outside, mine are looking good. I have a few inside as well which are way ahead of the ones outside. If you have only one plant I'd be inclined to keep it inside, you don't want to find out later that the dreaded slugs/birds have eaten your carefully tended strawberries while your back was turned. Or you could try a window box, this is perfect size for strawberries, keeps them out of the way of slugs, and birds tend not to come so close to the house.
Shop bought compost will have enough nutrients for four or five weeks at least so you don't need to worry about feeding anything yet.
Good luck, you may get the gardening bug!