You can't. You need to see that Pokemon before asking for it. You can also try the GTS Negotations and see if someone is willing to trade you the Pokemon you want/need.
Nope
yes
you have to have seen the Pokemon before
Yes u can, If u put a Pokemon in GTS You can still seek for Pokemon.
the gts is pretty simple, if you have a wireless connection, then you talk to the lady in the gts building in Jubilife city and she will connect you which takes you to a computer. On that computer, you can either deposit one of your Pokemon up for trade, or you can search for other Pokemon that other people have put on trade. If you find someone that has the Pokemon that is desired, and if you have what they are asking for, then you can trade with them no matter where they are in the world
Nope
i need to know how to trade Pokemon on gts after i put Pokemon the offering Pokemon and the Pokemon i wanted but i still cant trade with the Pokemon
yes
You can't check what Pokemon are up for trade beforehand.
You can to a friend wirelessly but not over GTS it will say on the gts "that Pokemon may not be offered for trade"
Get on GTS.
you have to have seen the Pokemon before
Yes u can, If u put a Pokemon in GTS You can still seek for Pokemon.
GTS stands for global trade station, it is located in goldenrod city to the west and requires wi-fi connection, you can put Pokemon up for trade in exchange for a Pokemon of your choice that you have seen in the wild or with a in game trainer, you can also view battles and see other Pokemon boxes.
At the GTS in any Pokemon Center.
Because you havn't seen it (also if you dont have a natinal dex)
the global trade station