I'll be honest with you.. I'd love to help you out, but I'm not sure I understand your question. Maybe you could clarify what you are having trouble with?
I'm going to take a guess on one thing...
If you're asking how a 4 and 5 string bass relate to a six string bass...??
a 5 string bass is generally strung like the the bottom five of a six string
a 4 string bass is strung like the middle four (EADG low to high)
but if that's not what you're getting at let me know.
As a fellow new player I think you should go get a four string to start on. A friend who is helping me started on a regular bass, got proficient on that, then graduated to the six string. Just a thought.
your sooooo very Blessed to have a 6 string! Especialy at your age! Your hands are strong when you are young .Enjoy that! As far as your Q.I belive you can learn just as well on a 6 ! Think of it this way,in boxs. an entire scale can be in four frets'n'3strings/2frets4strings,Its all about the patterns.And its the same up 'n' down the neck.On bass you can play walking chords within 3,or 4 frets ; yet you can keep walkin as far as you can go down the neck(box to box)with a6 string you can walk even further.As far as the right hand thumps the string,the LEFT HAND,presses down on the strings and does the walkinGod Bless! hope this helps theres so much more to tell.