i was looking at this tab and it had both 8th and 16th notes in a bar. so should i alternate pick on both the 8th notes and the 16th notes or should i alternate pick only the 16th notes and down pick the 8th notes?

heres a screen shot of the tab
down pick every note except for the sixteenth notes.
"I will endure, hide away...

I would outrun the scythe, glaring with failure"

Opeth - April Ethereal
Its up to you, the easier way is to downpick...if you wana challenge yourself, go ahead and alt pick everything....if you're into the tone and how the notes sound, play both ways and see which one satisfies your ears....
"Well, yeah, sometimes I get a little too creative."
~Bruce Dickinson~

"Various equipments"
there isnt a right or wrong way to do it, just do it how you're comfortable, personally I would alternate pick it all because you can get a steady rhythm that way...
Fenix by Young Chang 1989 Stratocaster <3