I began tinkering away on a piano from my early teens. I taught myself to play Bass guitar in 1981 and began playing in top-40 and pop cover bands a couple of years later, and then continuously for over a decade afterwards.
I also play saxophone and it's still one of my most favorite instruments to play. I also enjoy playing acoustic guitar and the harmonica, and still get a kick out of jamming to along to my favorite Beatles, pop, folk, & gospel tunes, etc. I have an in-depth understanding of music theory and am keen to share my knowledge with learners who are currently at beginner or intermediate level, and who are wishing to expand or accelerate their musical knowledge and development.
How to learn the notes on your BASS:
Start by working on memorizing the notes at the fret markers at the very least. Make it a point to work on at least the first three fret markers, for starters:
E string = G A B
A string = C D E
D string = F G A
G string = A# C D
...notice how with the exception of A#, these correspond to all the white notes on a Piano.
Then over time with regular practice you'll start to subconsciously fill in the in-between notes.
Remember that the whole fretboard just repeats after the 12th fret.
Remember also that the top 2 (thinner) D & G strings are exactly the same as the bottom 2 (thicker) E & A strings, but just two frets further forward - i.e. Octaves!
TIP: Yes, it's totally easy to use octave patterns (together with cross-string 5-fret, 7-fret repetitions) to skip and jump to anywhere on the neck, so why not memorize the note names as you go along?!
Also remember that a standard Bass guitar is tuned in fourths, E A D G (which is like the Circle-Of-Fifths backwards!)
Interesting trivia: This is the complete reverse of how a Violin is tuned i.e. Violins are tuned in Circle-Of-Fifths order.
Very important: if you haven't already done so, make sure to memorize the Circle-Of-Fifths, forwards and backwards,
this knowledge is crucial, regardless of what instrument you play.
A musician not having in-depth knowledge of the the Circle of Fifths is like a Physicist or Chemist not having very good working knowledge of the Periodic Table Of Elements!
i.e. It. Is. Absolutely. Essential. !!!