People raise the glass and say Kanpai- then we take a sip-keep the glass down and then clap - to kind of signify the start of the event /party etc.
In Japan, we say Kanpai when we do a toast. In corporate events, parties with friends or your host families, you might have to go through this... In corporate events normally they might have a speech - after which the speaker will raise the toast and say Kanpai. Then people raise the glass and say Kanpai. Then people take a sip, keep the glass down and then clap - to kind of signify the start of the event /party etc.
(after this the food is opened for guests and one can go for food or continue with the drinks etc)
If you dont drink alcohol, thats fine. Just be sure to have a glass with orange juice or ginger ale etc in it. In personal parties too, instead of just saying that you guys go ahead as I dont have alcohol (putting your host into discomfort) its better to have something in hand - gives them a notional feeling that you are not left out - while you dont have to go out of your way and try alcohol.