The first five minutes
Pick a plan, train, see what happens at the end. That is all.

First, a plan
Routines ships the catalogue programs ready-made: pick the one that fits your days and goal and adopt it. Adopting COPIES the whole thing (routines, sets, reps and rests) and from then on it is yours: change whatever you want, the original stays where it was. If you already have your own plan, create an empty program and build it by hand.
Then, train
Today shows the routine that is due, based on the days you marked, with its exercises and how long it usually takes. One tap on «Train now» and you are in. For something one-off, «Free workout» starts blank and you add exercises as you go.
And when you finish
Hitting «End» brings up the summary: sets, volume, new records, the XP you earned and any runes you unlocked. The workout is saved to your history in full, and from there it can be repeated as is another day.

The short version
Adopt a plan, train, read the summary. Everything else in the app is a consequence of those three steps.
More on How the app works
Inside the workout screen
The one you will use most, and the one hiding the most.
Routines, programs and other people
What each one is, where they come from, what sharing actually sends.
What each chart is looking at
Progress has six things and each answers a different question.
Cosmos: what is shared and what is not
Box by box, and what never leaves even if you tick everything.
Your data: cloud, backups and importing
Where your history lives, how to get it out, how to bring it in.
This is general information written from the training literature, not medical advice or a personalised plan. If you take medication, have a health condition or something genuinely hurts, the person to ask is a healthcare professional.