If your aim is to learn just the songs you need to play - say for an on-stage set - then the best use of your time may be to work on those songs and practise new chords as you find you need them
If you want to become a more confident and competent musician then your question is a good one because focused and structured practice is the way to go.
I would suggest:
1) Learn movable chord shapes. By learning the shapes for types of chords (rather than all the individual chords) you'll be able to play unfamiliar chords by moving them to new positions. For example the BMaj shape of 4322 will give you a CMaj chord if moved up a fret to 5433, or a DMaj if moved up three frets to 7655. A DMaj shape of 2220 will give you EMaj if slid up two frets to 4442.
Learn a couple of shapes each for Maj, min, dom7, min7th and you'll have most chords covered without learning the fingering and position for each individual chord.
2) Learn scales the same way - by the shapes. The different shapes can be moved around the fretboard to give scales in different keys. Which scales will be most useful will depend on the kind of music you play. For folk, bluegrass, Irish etc the Major scales are probably most used, while for blues, pentatonics are a good place to start.
3) Learn the Nashville number system for identifying notes and chords. By thinking of chord progressions in terms of I, IV, V rather than C, F, G or G, C, D etc etc etc you'll come to understand the structure of songs better.
4) Try to learn to distinguish the sounds of chord types by ear - Major, minor, sus4, dom7 etc.
5) Try to learn to identify intervals by ear. You can use tricks to help with this - for example, the interval between the first two notes of the main melody of the Star Wars theme is a 5th, so that tune can be your mnemonic for remembering the sound of that interval. You can find other tunes familiar to you for the other intervals. Alternatively, just count up the Major do-re-mi scale to count many of the intervals between notes.
But in all this, keep practising songs. Try to see how scales and chords relate to each other and to the songs. Learn to recognise common progressions and patterns.
Music theory is useful, but only if it fits in with what you're actually learning to play. It's of little use to know all the scale modes if you can't play a song with them.
There is some pretty good software available to help with music theory and with learning chords, scales and the relationships between them
Check out Chord Wizard Gold or Silver, and Chord Wizard Music Theory. Commercial products, but demos are available. I have used these for years and found them very good.
http://www.chordwizard.com/products.asp (NFI).
Good luck with whatever you're aiming for. :shaka: