start it and continue working as if it wasn't there. then read or learn one thing or two about it, and use only that.
the first thing to learn is how to attach to an existing session. that alone can be useful.
if you scroll a lot on your terminals, you'll want to learn scrolling in tmux.
if you use tabs or multiple windows, you' want to learn how create and switch windows in tmux.
beyond that every feature in tmux is additional to your regular terminal use so you can pick and choose the features you want to learn as you go along and otherwise continue without changing the way you work.
i have used tmux for a decade and i am still learning new stuff, like how to effectively use split windows.
Or is there anything was changed?
I ended up using `minicom` instead.
Alas, serial ports are pretty nifty but I get the impression that they are distinctly becoming a lost art
I used to use tmux much more heavily locally before I switched to a tiling window manager, now I only use it when I need to do a lot of work over SSH or am using an unstable connection or long running process etc.
Since I moved exclusively to i3 some 10 years ago, I find myself seldomly using screen/tmux anymore.
The splitting, moving and switching of windows is just more convenient. Tmux has been relegated to start long running processes on remote servers, and remote pair programming sessions.
I could see myself using tmux more if I could find a way to get a more seemless experience when having to scroll panes, copy/paste, handle $TERM properly with vim (I always end up with partially refreshing vim colors under tmux), etc