You wont need Japanese as plenty of signs ,maps etc in english and yes some people speak a little english.
a few basic friends in english help so bonus for you if your doing a bit of study.
The Ice Festival in Sapporo is nowhere as good as it used to be due to city budget constraints but for a first time view its still worth checking out.
My advice hit it late afternoon for a wander through, then go warm up with some food and go for another look once its dark as place is all lit up and looks pretty good.
Not sure if they run it anymore but they used to setup a smallish big air jump in Odori with Japanese pro riders going for spots in the Sapporo Big Air which is also worth checking out.
As for car related events in late Jan through Feb the Osaka Messe will be on just keep an eye on this link for dates http://www.automesse.jp/e/index.html
In my as good as Tokyo Auto Salon if not better.