Will -- easy does it dude,...
read up and research things before you order the whole store! Have you looked at the GLN section here yet, and did you see the free 1000g offer they have for AFN members? All you pay is shipping, minimal $! ....Also with GLN/Megacrop, you don't need so many other nutes; that's the whole point of using MC, it has it all in there already... only thing I'd add in is a higher PK bloom booster, to use sparingly during bloom; there are lots of choices there including what GLN offers, but as mentioned in PM, look at the P-K #'s; if they're big, you use less in proportion.... Milder bloom booster nutes like GH Kool-Bloom liquid (0-10-10), Atami 0-15-14) are good choices, just....so no Ca-Mg needed, but it doesn't hurt to have it in hand just in case,... you have plenty of time to deal with this meantime,....
As for soil, I hear some good things about Dr. Earth Organic potting soil, readily available at garden centers, so look and call around for that,... worst case,
Happy Frog is a fall-back option,... and get that Accurate 8 soil pH probe (Amazon... Control Wizard products) for
in-pot testing,.... if you want to do this right, you need the equipment to help you.. it's an investment, but the best way to avoid trouble is to monitor pH of both water and nute solutions,.... an inexpensive TDS (total dissolved solids) meter is wise, to test the strength of your nute solution, and to know what your water is like for hardness (mineral content), which can be a serious issue if it's bad! (mineral build up, basically Calcium carbonate can start to screw with pH and nute uptake).... The point here is to head off trouble and mistakes by prevention and monitoring, instead of chasing fixes to f'-up's
..... By knowing the right info dialing in your inputs before going into the pot, you go a long way down the road to avoiding in-pot pH issues,... If pH goes too far off, it screws with the nute's chemistry, and renders them unavailable for the plant to to take up,.... you don't have to fuss
every time, but at first, you kinda do until you gain familiarity with things....
Are you stateside? If so, I have another great option for you... Mephisto's soil amendment is made by own GBD here, a simple dry mix-in product that should see the plant's nute needs through the whole grow, nothing but good quality water needed,... this is usually pretty solid, but I'd still have some basic nutes around to supplement IF needed,... all you do is mix up a batch of soil with this in it (2T/gal soil), put a layer in the bottom half of the pot, then fill in with plain soil on top so the seedling has mild soil to start in,.... To get it, just PM GBD here,.. It's only $27 bucks shipped, and treats a whole 1.5cf bag! And it's well documented in grows here-