where do i get my tracks to upload and where do i put downloaded tracks into?

you want to upload nations tracks to tmx or to a server? about servers i really don't know because i don't play at the moment and probably most servers are already switched to tmn forever (i guess)... here on tmx just click on 'upload tracks' and follow the instructions...
downloaded tracks go into '...\trackmania nations eswc\gamedata\tracks\challenges\downloaded' as far as i remember...