If i set to US and time zone changes, will it affect me playing animal crossing since its real time?
Just set it to your local time can liao. The game will give you 2 hemispheres: North and South. The creatures appear based on the months for both hemispheres. Example: Now Northern can catch Scorpions and Southern can catch Tarantulas.
For me I only time travel to sell turnips and finish the upgrades. Maybe next time I'll time travel to complete my creature list.
Things to note is you can't terraform the end of the water stream and beach area so when choosing your island must see the layout. Your "Resident Services" building also can't be moved. Before you buy the game just watch videos so you'll get a rough idea on how you want to design your island.