A tiny dot of white enamel paint (like that used to touch up appliances) on the side of the neck can mark the frets, and wears off all by itself eventually, after which you won't need the marks.

Teflon tape-wound strings by Innovation are very easy on the fingers and sound great. Strings cost a lot but last a looooong time.

It's easy to be a beginner on bass but takes a lifetime to master and most never get there. I'm a perennial beginner but have often started people off on bass with some simple lessons. One thing I tell them (that was told to me):

Whenever you fret a note with your left hand on the neck as "one," you can usually fret the same position on the neck on the string behind it as "five" or pedal note. For example, in the key of E, if you press down the E note on the D string for "one" you can then press down the B note on the A string for "five" afterwards, same position on the neck, different string. If one string is played open (not fretted) you can play the string behind it also open. (By behind it, I mean the lower string where the strings are E/A/D/G and E is the lowest string.

By one and five, I actually mean (in 4/4 time) beats one and three. They talk about bass players playing one/five/one/five because of how they usually play the root and fifth of the key.

To remember the strings, I tell people "Eat All Dead Gophers" for a memory aid.

Remember that the bass needs to drive the tune in bluegrass and old-time, right at the front edge of the beat. In blues the bass is at the back edge of the beat. But you'll be responsible to keep the tempo as much as possible unless the others run away with the song and you have no choice but to catch them!

The bass is so much fun to play, kind of likc playing an instrument and dancing at the same time. Move with it and enjoy!

Hope this helps.