Are you in USA? If so, lots of American options for plants. Buceplant.com is good, I have a friend who has gotten some nice stuff.
Look for easy plants that don't require a lot of care, such as cryptocoryne wendtii, Brazilian pennywort, anubias barteri nana, anubias golden nana, bucephalandra wavy green...
The anubias and buce you tie to wood or such, don't plant them in the substrate (sand, gravel, etc). Pennywort would prefer to be attached to a suction cup or left floating, but it would be okay planted too.
Crypts melt at first but they tend to bounce right back. They're pretty hardy, low light plants. Not super needy either.
Water sprite is another super good one, just leave it floating and it can create a lovely canopy.
All of the above are beginner friendly, don't need much outside the odd weekly dose of fertilizer and all are suitable for a 10 gallon.
Check some plant sales sites for "Low Tech" plants. Most of these are fairly good. Avoid sword plants for a 10g. Theyre good low tech plants but they definitely get huge and will outgrow it.
(don't feel bad about elodea, it's known to melt in some conditions for many people despite being an "easy" plant.)
As for fertilizer, NilocG Thrive comes with a pump dose, but downside is its a tad pricy to some (cost $36 CAD for me) BUT it's a really good fertilizer that has all the nutrients most plants use (this can vary due to your own particular water chemistry, but usually this isn't a big deal). But it would last you a very long long time for just a 10 gallon, with low tech plants. Maybe once a year or so for you to rebuy. Don't waste your money on Flourish or Flourish Excel. Excel is not a fertilizer or liquid carbon and does more harm in the long run. Flourish is okay but it is meant to be used with their line of individual nutrients so is not a complete fertilizer all in one. So prone to a lot of deficiencies with using it as most tend to use it as.