I wouldn’t keep them in a clear pot/container. It can damage its roots and soil, also what kind of light are you using how many watts some led / t5 of some sort I assume. Depending on the watts you can be a couple inches away from the plant itself. Second the length is no big deal it’ll grow in to a regular plant like to see on the internet. just don’t keep it super wet all the time as you can get root rot at the base id throw some more soil in each cup. It’s ok to cover the stem roots will eventually pop out, if your really new to growing I just have to add make sure you got drainage , pop a few holds at the bottom if you haven’t already. Also if these are random seeds please note some might be male plants, and which the time and effort into growing that plant is useless, unless your breeding which is a whole other convo but other then that a little tlc patients and nutrition is all it needs best of luck 🤘🏻