I think try and narrow down from what you do (or really don't) like:
Are you outdoorsy or does the thought of wearing waterproofs make you want to cry? You can count in or out stuff like outdoor swimming, stand up paddleboarding, hiking, camping, horse riding, cycling etc.|
Do you like exercising or prefer to be comfy and horizontal (like me, haha) - then you can count in or out crossfit, bouldering, Zumba, pilates etc.
Do you like being crafty or does the thought of something fiddly fill you with boredom? That covers painting or pottery classes, cross stitch groups, knitting groups.
Are you remotely interested in politics/local governance/helping causes? If so, there's campaigning for local causes or politicians, joining a local residents' group, joining a local foodbank or street homeless support team and helping out.
Like animals? There's volunteering at shelters, being a dog walker, horse riding, etc.
Want something you can do at home but meet others virtually? There are games (everything from Dungeons and Dragons to fun co-op strategy games), or puzzle solving clubs or online book clubs or cryptic crossworder groups.
Want something fandom related? There's cosplaying, fan meet ups, going to conventions, watch-along clubs for every TV show and franchise you could think of.
Like food and/or cooking? Cooking classes, 'curry club' type events, cooking for local homeless shelters...
Want to do something useful? Almost every charity ever will need volunteers - from admin to serving food to fixing outbuildings at animal shelters to sorting donations for charity shops to writing emails/bids for fundraising.
Do you want to/can you spend a lot of money, or not? Some hobbies (rally car driving, horse riding, pottery, collecting Warhammer, even some online games) can be expensive, some (online clubs, book clubs, volunteering, campaigning, running, etc) can be cheaper, and some are as expensive as you want to make them, so factor that in.
Do you want it to be regular, or ad hoc, or a mix? Park run, for example, you can do whenever you fancy but it's on regularly. Volunteering is usually set times, whereas you can pop along to a book club or debate club whenever you want.
So maybe think - "it needs to be out of the house, but not 'outdoorsy', I'd prefer it to be once a month/week/fortnight, I'm not fussed for it being charitable, I do want it to be cheap"... etc and then go from there!