As far as soil, I have never found anything at Wally World that isn't mostly peat moss with fertilizers already in the soil. Fox Farm Ocean Forest is hella expensive and you will have to look farther than Wally World, but it is the shit!

About temps/humidity, I found 2 different gauges in the hardware section of Wally World and another near some bird feeders and outdoor weather stuff. The cheapest was like $6.50 and just displayed current temp and humidity.

Another was like $7 or $8 and showed highs and lows for the temp and humidity (as well as current) for the last 24 hours.

good luck and keep us updated

o yea, and welcome to the forums. happy gardening

peace