I am not sure how accurate the information is but I think Dr. Foster and Smith has a write up on the care of both the plants you have. I think there are some decent planted tank websites which is also a good place to look if people here can't help.
I've never used root tabs, you'd probably have better luck googling them, but I think they are little slow release fertilizer tablets you shove under the substrait by the roots/ base of your plant.
Flourish Excel is a great product i've heard too, BUT it will kill marimo moss balls. It kills algae. So be sure to look up the plants you have and make sure that it can be used on them before you treat your tank.
Good luck researching and grats on your new plants the dwarf baby tears are so pretty!! :)
Betta Fish are like potato chips, it's hard to have just one!
Arm yourself with knowledge. Consider advise. Make informed decisions.