I'm not sure what i'm doing wrong, but i loaded classic mode via the red cart in the gateway menu, and when in classic mode [it shows my emunand 8.1 screen btw... is that classic mode???] switched to animal crossing and nothing shows up.
Wait, you're saying you're trying to start Animal Crossing from the Gateway card while in Classic mode? In order to run games from that card, you need to be in "Gateway" mode. To access that, just insert the red card into the system and don't hold any buttons while launching the DS profile exploit.
conversely i tried booting into classic mode from the gateway menu with the acnl cart in [ignoring the red card, it sez not all features will be available without red, hit x to continue] and then it freezes.
That's normal. It's Gateway's way of forcing people to buy their products in order to use Emunand.
also since i would play my genuine cart online... does that mean i have to turn on wifi in 4.5 sysnand? sorry for the noobness.
If you're playing the game on Emunand, then no you do not need to keep any Wi-Fi connections saved on the sysnand.