Symbols used ?

Going by the examples you've provide:

13pb15 - no idea. I don't know what pb is supposed to represent. It's worth noting, though, that some tabbers will occasionally use their own notations instead of the universal givens. I'd have to see the tab itself, maybe then I could figure it out from context.

5h6h7 - “h” stands for “hammer on.” You start with your index on the 5th fret, hammer your middle finger onto the 6th fret, then hammer your ring finger onto the 7th fret. You're using the sudden pressure of the applied finger to ring the note rather than picking it.

3s - no idea. I'd need to see the tab for context.

7————–7——- - also not sure. Again, I'd need to see the tab.

3b - typically in printed notations, b means bend.

5/7 - / usually means slide up. So you'd slide up from the 5th fret to the 7th

And welcome to bass guitar. Here's to hoping you enjoy it as much as we do!

i found this while looking for the tabs for “Badge” by Cream.

Duration Legend
———————————————
W — whole; H — half; Q — quarter; E — 8th; S — 16th; T — 32nd; X — 64th; a — acciaccatura
+ — note tied to previous; . — note dotted; .. — note double dotted
Uncapitalized letters represent notes that are staccato (1/2 duration)
Irregular groupings are notated above the duration line
Duration letters will always appear directly above the note/fret number it represents the
duration for. Duration letters with no fret number below them represent rests. Multi—
bar rests are notated in the form Wxn, where n is the number of bars to rest for. Low
melody durations appear below the staff

Tablature Legend
————————————————
h — hammer—on
p — pull—off
b — bend
pb — pre—bend
r — bend release (if no number after the r, then release immediately)
/\ — slide into or out of (from/to “nowhere&rdquo
s — legato slide
S — shift slide
— natural harmonic
— artificial harmonic
n(n) — tapped harmonic
~ — vibrato
tr — trill
T — tap
TP — trem. picking
PM — palm muting
\n/ — tremolo bar dip; n = amount to dip
\n — tremolo bar down
n/ — tremolo bar up
/n\ — tremolo bar inverted dip
= — hold bend; also acts as connecting device for hammers/pulls
— volume swell (louder/softer)
x — on rhythm slash represents muted slash
o — on rhythm slash represents single note slash

Misc Legend
———————————
| — bar
|| — double bar
||o — repeat start
o|| — repeat end
*| — double bar (ending)
: — bar (freetime)
$ — Segno
& — Coda
Tempo markers — = BPM(8/16=s8/s16), where s8 = swing 8ths, s16 = swing 16ths