Okay, well fisrt off that bark mulch stuff in the soil isn't helping you.
Second I can't really tell with the bark but I get the sense it's REALLY wet, too wet.
It's going to need a much bigger pot soon anyway, so when you are ready to repot into something like a 3 gallon container with LOTS of drainage, use good compost with plenty of perlite in it to make the soil lighter.
Fertilizer you can get when you go to buy the soil. It is definitely N deficient, among other things. Depending on where you go, you can get good compost at the farmers supply, or if walmart/home depot are your only choice, miracle grow ORGANIC is safe to use on cannabis. And then for fertilizer, one with a high first number is for veg, and a high middle number /LOW first number is good for flowering, which will start very soon.