Sorry for the harsh tone ... but as mentioned above ... if the chain breaks it could be disastrous. I'm a chain nut because I learned the hard lessons you're learning now a few decades back. I've seen chains break (rare these days), ruin the engine case, lock the wheel and send bike and rider into a ditch. Not a happy outcome. A broken chain at speed should be avoided.

This is perhaps one of the most common things those "new to bikes" miss. They ignore their drive chain.

The "main bearing" comment maybe should have read "Main Counter Shaft bearing". the Counter shaft is the shaft the front sprocket goes onto. There is a bearing that fits into the engine case and seals that shaft. These sometimes fail or leak ... easily fixed if you can find the right bearing. (common size)

Looks like you've got lots of local help here ... gotta love the HU community!

Glad to read you're doing bike research and learning your bike. Big ups!
It ain't rocket science ... just basic maintenance. Step by Step.

The oil use is a bit worrying but as long as you keep the level up, you will be fine until you have time to sort it out and find the problem.
It could be a few things:
1. be consistent with the way you check the level. NOTE: Level will always be different when bike is cold as opposed to HOT. Is bike always level? Are you supposed to screw in dip stick all the way in? .. or not? (varies bike to bike)

2. Sometimes switching to a much lighter synthetic oil can cause some oil use. Use correct weight oil when possible. (10/40 ?)

3. Don't worry about mixing & matching oil. Regular non synthetic is fine to mix with semi or Full synthetic oil. Mixing brands is fine too. JUST KEEP the level up ... but never OVER FILL

4. If the valves are well out of spec, this can sometimes cause more oil use.
5. If the crankcase vent hose is pinched, kinked or blocked, this can cause oil use or pumping of oil into Air Box.
6. Check your Air Box and Air Filter ... is there oil in the Air Box? Is the Air Filter soaked with oil? If so, then you may have OVER filled the crankcase with oil ... or rings are bad. Over filling is not good. Make sure you check the oil level using Honda's recommended method.

Good luck sorting all this out!