Hello and welcome to rff.
I just bought a lllc last week, but have owned a couple of lla's in the past.
Given your experience, I'd suggest you set aside the supplementary lenses for a bit, and get yourself used to rangefinder focusing and manual exposure setting with the basic camera with normal (50mm) lens.
Our cameras have an EV interlock. When you adjust the shutter speed, the aperture setting changes along with it to maintain the same exposure. You must move a little tab near the aperture setting outwards to unlock the 2.
The camera has an uncoupled exposure meter built in, but it's accuracy is unknown at this point and its exposure recommendations need to be manually set on the camera. This does not happen automatically.
Best to get a handheld light meter or a light meter app for your smart phone.
Do some reading about manual exposure settings (shutter speeds/aperture) on the Internet.
I'm happy to answer any questions you may generate from your readings.
If you're dying to expose some film, get a roll of 400iso.
If you are outside on a sunny day with your subject in the sun .(not shade) set the exposure controls on the lens to f11 and 1/500sec, focus on your subject, compose, and shoot.
If your subject is outdoors in the shade, set exposure to f8 and 1/125sec.
If you are shooting in the evening under artificial light, set the exposure to f2 and 1/30sec.
These settings are just guidelines and should provide useful results, but a light meter is best.