Tomatoes likes a rich soil but if the nitrogen is high it's going to cause green growth which you may not need or want at this stage. What size container have you got them in? No, changing the soil will not help. seed
have all the nutrients in them they need for the first 30 days of growth so during that time they don't need anything added so a good potting soil is just fine. Tomatoes are a lot like weeds
, they do better when they aren't fussed over.
You know plants go through transplant shock when they are moved, so you might want to only transplant them once after they sprout and before they are transplanted outside for the summer.
I know some people suggest transplanting to a container now bigger than one inch larger than the container things are currently in but I've never had a problem putting seedlings
in the containers I plan to grow them in and not transplanting at all. Mostly I started doing this because of the transplant shock and because I'm a clutz and I killed some of my plants when I tried to transplant them.