I need to buy soil from a garden center like Lowes. what is a recommended mix
I would say anything with a peat moss base and NO TIME RELEASE!!! I know they sell ProMix there which is a really good medium for cannabis. @Myfriendis410 uses promix and he is a very good grower.
Scott’s has some products that use organic ingredients but what you should be more worried about is the native PH of any soil used. Most in my experience are too low PH to do a good job. Unfortunately the problems manifest during flower which makes it hard to rectify.