Newbie accessory question

I wouldn't run anything off the battery directly.
The ones that will be used when the engine is off, I might tie in with a terminal post.
The ones that will be used when the engine is running above idle speed, I might tie to the alternator output with a terminal post and/or additoinal fuse box.
You could use the empty accessory fuse slot in the existing fuse box - if the currents will not be too high.
There is only one slot there, so it can't be used for things that you wan to work with the key off, and also work with things that should work with the key on.
Each accessory should have the power it will need listed somewhere. It may be in Watts, it may be be in amps at 12 or some other voltage.
Get all that information and you can start planning a design for adding them on.
I think it likely to make sense to use one of the optional power feed wiring methods. And it almost certainly means using a later alternator.

Basic power circuits for 67 is explained in this post so read that first.
headlights not working