confused on story

[Future Angel]

i was always kinda confused in ffx story, i started it again and feel so nostalgaic!

but like

SPOILER!!:

so basicaly tidus was just a dream character? was he based on someone from zanarkand before? that part made no sense to me, cuz also chappu, wakkas brother looked like him - what was up with that?

also in begining of ffx when u go to ur blitzball game theres a guy narrating aobut a coffee shop or something - who is that? O_O

got a few more qs but cant think of em atm!

also how is auron able to hop between spira and 'dream zanarkand"?

thanks