If you like music, go check out the bars and clubs along Queen Street. Like "The Cameron" for upstart music and comedy acts, "The Rex" for jazz and blues, just as a couple examples. Probably searching online will get you close to the kind of places you would want to go, for good events with old friends and to make new ones.
My advice on this is to volunteer events like tree planting and community events. You'll meet less people then some other methods, but the people you meet are usually the kind of people who volunteer. usually they're also looking to meet new people. Also you get all the benefits of volunteering
Honestly, havn't tried much since I moved here. So that's the only one I know of for general opportunities. Depending on your intrest or values you can usually find organizations specific to what you want.
Habitat for humanity might be good if you want physical labour. Looks like they have some shifts open at their restore locations open now.
The humain society if you like animals, you cam also just ask your local vet clinics if they need any help. I did this as a kid and enjoyed it.
I worked with the company of fool theater group in Ottawa wich was really fun. I assume toronto has simular small theater groups who could use a hand. Somtimes it's best to just send an email and ask. Unless you need hours for somthing there's no need for any formality.
I only suggest some caution as some volunteer roles these days are just companies wanting free labor. I've seen this with a video game store in my home town. Owner was just exploiting my fellow nerds and was being a huge jerk about it. If it feels wrong hit the bricks. Find somthing else.