ok...
1) get a larger container...anything...just drill holes in the bottom of it...party cup grows are meh...
2) dont get all OCD over it...give it light...give it water when it NEEDS IT..after the soil is dry...
3) get real potting soil and a bag of perlite and mix it up at a ratio of about 3:1 soil
erlite...you need airy soil or your roots will suffocate...dont just dig up dirt out of the back yard...
4) just use string to tie the branches down and put it at 12/12 about a week into the grow to keep its height stunted...
So...don't overanalyze it...keep it simple...its like growing any plant...dont overwater as you'll strip the nutrients out of your soil that you need...and ask questions along the way