Song 14 - "Blitzkrieg Bop" by Ramones

60 yrs old, new to both bass and Bassbuzz, on module 6 of the B2B course. i thought id try and get one song dialled and love blitzkreig bop so thats my goal alongside the course.
couple of questions… ive found the tab in the ‘50 songs’ section so can work on that, starting slow and hopefully building up. ive also been watching your videos ^^^.
i notice that some of you play different strings/frets to the tab so just wondered why. just preference? for instance the last video i think played an open A instead of E5. a couple of others were sliding down to A2 instead of E7. it just seems easier to keep everything in that 5-7 block, so curious as to why the differences.
last question. how are you playing along to the actual song? just finding it on spotify say and playing along? the tabs on here are just the tabs, no other instruments or vocals, so i just wanted to check im not missing anything and there isnt a ‘bassless’ version of it on here somewhere to add your bass to when playing.
thanks