Newbie Help - Channel Structure + Relationships

I’m back to EEv4 after many many years away and totally new relationship fields etc and could use some how-to advice from the hive mind!

I’m working on a small hobby project. I’m building a mobile site to use as a pocket companion for a role playing game my friends and I play (nerd alert!). The idea is that it has a few sections for reference and member-specific character sheets. The reference sections are straight forward in my mind, but I’m struggling how to structure the character sheets since they will have relationships.

My idea for the character sheet channel entry form is that it will have some of its own fields (stats, etc) but for the “known spells” section I wanted to have a dropwdown field that pulls in the spell schools (another channel or category?), another dropdown field that then pulls spell names from whatever spell school the user selects (not sure if those should be child fields within spell school channel or a channel on their own), and lastly another field that pulls the description of the selected spell. I’d like those 3 items within a repeater to allow users to build a list of spells from various spell schools. Character sheet entries would be outputted to a list of characters and then a single-view character sheet screen on front-end.

Is this possible for channel entry forms or would I need to create a stand alone entry form template on the front-end? Any advice on the best way to structure the data for spell schools and spells? Some structure thoughts below:

Spell School (channel) - School description (field) - Spell 1 name (field) - Spell 1 description (field) - Spell 2 name (field) - Spell 2 description (field) - etc

or

Spells (channel) - Spell school (category) - Spell name (field) - Spell description (field)

Any help/advice greatly appreciated!