You shouldn't need a teacher to tell you how to play a bass line. Or a YouTube lesson, TAB site or other method. If you work on your ear enough so that you can recognise simple intervals then you're in a great place to start figuring it all out yourself.
You ears are your greatest strength. I know that when you first start it can seem impossible to hear bass lines and work them out but, don't worry, it's not that bad once you have a few tools under your belt. Intervals are a great place to start.
The basic idea is to learn an interval shape (or shapes) on the bass fretboard and then map that shape to a famous melody.
The menacing two notes from Jaws outlines a minor second.
The bass line movement in Dreams by Fleetwood Mac is a major second.
The first two notes of the Smoke On The Water riff.
Do Re Mi from The Sound Of Music contains lots of interval learning opportunities! The lyrics 'a female dear' outline a major third.
The Addams Family or Blackadder are two great theme tunes for the fourth. The first to the fourth notes of the Addams Family is a perfect fourth as is the distance between the first two notes of the Blackadder theme.
Sharpened Fourth/Flat Five
It's a sharpened fourth in, say, a Lydian mode, and a flat five in a blues scale. Either way it sounds the same.
The first two notes of the vocal line in The Simpsons theme tune is a sharpened 4 (and it is a #4 not a b5 because it comes from the Lydian mode).
This is a proper solid interval found a lot in bass lines.
The first two notes of the Star Wars theme are a fifth apart.
Another good one is the guitar intro to Wake Me up When September Ends by Green Day.
The synth riff on Usher's Yeah! features a minor 6th. It's also used a lot in rock songs and ballads.
Here's an excellent way to remember this interval: Donald 'Duck' Dunn's classic bass line on Eddie Floyd's Knock on Wood.
The first line I used to lock in the sound of the minor seventh was Flea's opening line on Red Hot Chili Peppers' Transcending.
The bass line on There's Nothing Like This by Omar is a cool example of the beautiful sound of the major seventh interval.
The octave is one of the most common intervals for bass players, along with the major and minor thirds and perfect fifth. My Sharona by The Knack is an easy example to grasp.
There you have it. The intervals up to the octave. There are intervals above the octave but they are just the ones you've learnt here up the octave. You can add these intervals into chords and construct all kinds of lines and solos using them.
Think about it: any bass line is just a series of intervals one after the other. Learn the sound of them and you will be figuring out bass lines by ear in no time.