I think it’s a good idea to get a few bought in seedlings planted. Lollo Rosso and little gem lettuce and a few carrots. We are almost (just about) out of danger from frosts but not quite warm enough for reliable germination.
We have a couple of small greenhouses I can sow seeds in which will be ready about mid May. I don’t expect too much from the carrots, you have to be a little rough to seperate the roots so they may not grow well, they can be sown when the temperature rises a bit.