A lot depends on the type of trip you are on.
Site seeing: CN TOWER, the art galary of Ontario, the royal museum, the Ripleyโs aquarium and more.
Restaurants: Toronto likely has the most cultural variety of restaurants in the world, just google Caribbean, Italian, Greek, Asian etc. One of my new favourites is Miss Likklemore.
Baseball season has started, so why not catch a game at the Rogerโs centre which is right beside the CN Tower.
Parks: have a picnic or go for a stroll by coronation park which is a large park at the marina of Lake Ontario, you can also walk along lake shore to harbour front where there are a lot of activities for friends and family, or walk the other way to high park, which has bike trails, parks, playgrounds etc. Also, take a fairy from harbour front to centre island where there is a beach, rides, games, more parks and plenty of other festivities!
Spend a spa day at Hotel X, while enjoying the view of the lake.
Night Life: Go for a walk after 10 am along King Street West where there are many lounges and clubs to enjoy. However there are many others spread out around the downtown area.
Hope these help.