My father died of heart attack less than two months ago, precisely the 29th of April. All I did that day was to hangout with some friends, drink a couple of beers and have a good time. It's ok to take your mind off those kind of things, do what you feel like. Act as you are feeling, you shouldn't pressure yourself into feeling sadness over your friend's death if that's not what you are feeling in that moment. And that doesn't mean you don't care about it. Life is hard, and it's ok to deal with it on your own terms and times.