i have recently come across a few picking lessons in tab form and it uses alternate picking but i was wondering because it says on some parts to do a downstroke on the string above and and upstroke on the string below, should i ignore this and just use upstrokes to move up string and downstrokes to move down strings or what?

just cus i am a patehtic picker and i get confused at alot of picking things.

Dont ignore that, that is alternate picking! When mastered you will be able to pick alot faster and cleaner. Keep in mind it is one of the hardest picking techniques there is so just take time at it and you will get it!!
It depends, the second option you mentioned would be called economy picking and is useful in its own right. I'd suggest that you do that practice routine with strict alternate picking for a while, then switch to implementing economy picking so that you become proficient at both.
well with strict alternate picking you should do a downstroke on the string above and then upstroke on the one below, it seems stupid at first but once you get the hang of it it flows really good
As previously stated, that is eco-picking.

Both eco-picking and alt-picking are useful. Learn both. They give different tonal qualities and are useful in different situations.