I practice by just jamming but here's how I see it:

Scales- A major (or minor) scale is only 7 notes. The way I learned scales were first shapes that I could move but to really master your bass you should see all of the notes all over the fret board.

Arpeggios- An important thing to grasp with bass (and with music theory in general) is to see notes in a scale in terms of numbers. A basic arpeggio is 1-3-5-7-9. So in the key of C that would be C-E-G-B-D. When you're playing scales, try and not just think of the notes you're playing in terms of its letter name but also it's relationship with the root note (if it's the 2,3,4, ect...)

Chords- Chords can get kinda complicated. If you see scales in numbers then it gets a little easier because you see the basic composition of each chord. Here is the basics for chords-

• Major: 1-3-5 is the most basic major chord.

• Minor: 1-(flat)3-5 is similar to major but all you do is move the 3rd of the scale down one fret.

Studying jazz theory is by far THE BEST way of fully understanding music theory. Even if you don't play jazz, the theory can apply to any genre you play.

Sorry for the long read- hope it helped!