Your post makes sense...your off to a good start.
The next step is to learn the major and minor scales (which are related to the pentatonics)
You should also start learning chords/arpeggios, you will realize that generally speaking a bass lines moves through 1 chord for every 4 beats (1 bar) in 4/4 music (but not all the time). Most of the time the bassist will use the first note (root note, I) of an arpeggio on the first beat of each bar (also called a measure). Once you start learning how music moves through each chord in a chord progression and what scales go with each chord all this will begin to make sense.
The C major arpeggio for instance is C, E, G which is related to the C major scale. so if you where playing a piece of music and the chord progression was C-C-G-C you would emphasize the C, E, and G over the C chord and the G, B, D over the G chord.
Check out
studybass.com and then check out
teoria.com