for lack of a better answer..( i dont know what soil they sell in the US)
get a general multi-purpose compost, preferably saying "for seelings/re-potting"
then you can be more sure that its not going to contain loads of fert that will harm the young plants.
compost for mature plants is generally a bit hotter on the ferts and should be avoided.

avoid anything with added fertiliser if possible ie: if its called "mega hyper charge 2000 with extra steroids" it should be avoided.

then use about 25% perlite in the mixture.


thats your basic run of the mill grow media for soil.

or just ask the assistant for a "mild soil for seedlings"