Slight correction there: the possibilities are endless.
The main rule is: if it sounds good, it is good. There is no “fixed” order or something like that.
When you have, for instance, the C major scale, you have
C, with all of its chords. Major, minor, 7th etc…
D, with all of its chords. Major, minor, 7th etc…
E, with all of its chords. Major, minor, 7th etc…
Etc, etc…untill you reach C again.
One chord will sound better than the other, in relation to the scale your playing.
And there’s the A minor scale too. The relative minor of the C major.
Again, with all of it’s own chords you can use.
This may seem overwhelming at first, but a good startingpoint would be this:
know your major scales really well.
Know your basic triads.
And from there on out, it’s “just” adding or subtracting.
For instance: C major = C E G, C minor = C Eb G, C major 7th = C E G B.
It all starts with the triads. Those are your basic building blocks.
Scales, if you look at it, are “just” lists of chords, with their qualities. (major, minor, diminished, etc…).
If you know a scale, you know the chord. C major, D minor, E minor, F major…etc…
Hopes this helps!