Thank you for explaining all this and for those links, I really appreciate it.Tropicals love humidity, but even in a room without much humidity you can still have them grow well. A humidity tray is good to help catch water, but it doesn't do a whole lot for ptoviding humidity for the tree. You can help by taking a spray bottle and misting the tree 3-5 times per day. Just keep the bottle by the tree and every once in a while when you walk by it give it a few mists and that helps them. Plus in the summer you can take it outside and sit it in the sun for 6-8 hours per day. That will help get it growing well.
The ficus in the pic you posted is a ginsing ficus, I'd avoid getting one of those. They have big tuberous roots which actually go against one of the main goals of bonsai which is a nice taper starting from the nebari and going up the tree to the top. Look for things such as tiger bark ficus, golden gate ficus, willow leaf ficus (willow leaf are a bit harder to work with though). Something like this here would make a great start for someone just getting into bonsai and wanting a tree that they can enjoy and learn from
https://www.ebay.com/itm/Ficus-tiger-bark-bonsai/392233215872?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160908105057&meid=a3b5d9d3a2ba4462806b14ed2e5011bb&pid=100675&rk=1&rkt=15&sd=392233215872&itm=392233215872&_trksid=p2481888.c100675.m4236&_trkparms=pageci:0f066f48-2fa5-11e9-98bd-74dbd180a2a0|parentrq:e78016f01680ad7835f38d83fff99aa6|iid:1
Brussels bonsai also sells some good starter ficus as well https://brusselsbonsai.com/indoor-bonsai/ficus-bonsai/
I do keep a spray bottle handy for my plants. Mostly just to keep their leaves free from dust. Since I spend a good chunk of my day in that room misting often wouldn’t be a problem.
I’ll keep away from the ginseng grafted trees like you suggested.
I have so much reading I want to do. Hopefully I can learn as much as possible about basic care and training by spring. It will be too cold for the next couple months to order anything.