if you need to know the name of the track you are on press the track with the red led next to it. then on the screen in the lower left corner where the name of the kit is, it will say the track name for a few seconds.

to load a new sound on a track press the track key quickly two times on the track you want to load the sound. this is the same as Function+Sound then choosing sound browser.

the +Drive is not something you “go to” in the typical way you would go to a drive and load a kit,sound, project.

All Kits are not accessible and are kind of partitioned.
for example. a project holds 128 kits. but if you are working on project A, and you want a kit from project B you can not load it. Kits are contained in a project and the A4’s +Drive can hold 128 Projects.

Sounds are not partitioned and can be loaded from the +Drive from any project. because sounds are not just saved in the sound pool of a project (128 sounds in a project pool) they can be accessed by pressing function + Sound.
Then choosing sound browser or sound manager.

Tracks and patterns can be saved but they are saved to a single file hidden from the user. this file is saved with the project and is used for when you need to revert back to a certain state after experimenting etc.
each track can be saved and each pattern can be saved in each project.

keep in mind that the project separates everything except sounds.
Also each project has a sound pool of 128 sounds. the reason for the pool is.
When a sound is in the pool it can be loaded instantly from trig to trig on the same track in the same pattern. a sound that is not in the pool can not be instaloaded this way.