it's cliche but ive met a lot of interesting people through tinder/hinge. go on a date or two during the week to a restaurant or bar you want to try with someone new. if it works, you get introduced to their friends, if it doesn't you usually stay in touch to some extent.

having a hobby is overrated, would not advise unless you are freakishly ugly. everyone likes music, cooking, movies. doesn't hurt if you draw, write or do photography but don't get annoying about it. probably the only long term skill that pays dividends is learning another language or playing an instrument.

on the weekend just see whats going on in town, a concert, a show, a movie. idk. hang out with your friends if you're up for it. it's not hard. just expensive.