Amanda,
I was lucky to be born with both a green and wet thumb. I throw it into the dirt or the water and it grows. Being a water sign (Pisces) I can't help it.
Right now I have a pair of Avacado trees (two species) about two feet tall that I grew from pits, and I'll eventually try to turn them into Bonsai. When I was a kid, I grew a 2-foot tall lemon tree with a seed from my late dad's tea. It had tiny leaves and tiny lemons

.
By the way, the sword in the right center of your tank looks like E. parvafloris to me, which is one of my favorites. Larger Echinodorus are nutrient hogs, so if the leaves start to yellow, fertilize, girl, fertilize. I use those chelated iron tablets that I push down to the roots.
I'm glad you're getting the hang of live plants. The only downside is no more silver dollars

. In smaller tanks, plants do wonders for water quality stability.
Dave
I dream of L-Numbers . . .