I've had some success with sites such as Facebook Groups or Meetup. They organize events to connect strangers with a shared common interest, in my case casual hiking and board games.
As a 36 year old that recently moved yet again to a new city (the third time in my adult life), I've had decent luck joining recreational sports leagues. Lots of leagues will have options to sign up as a "free agent", which usually means you'll get placed on a team with other free agents, which tend to be others in the same boat of trying to meet new people. If you aren't necessarily the athletic type, bowling and kickball are pretty good options. I've found that most of these leagues (especially if you sign up for the novice/recreational level) are NOT very competitive, and most people are just out to have fun, meet friends, possibly have some drinks, etc.
One way to do it is through hobby groups which meet IRL. You can make friends in the hobby-space there, and then gradually start inviting them to things that are not related to the hobby (becoming more of a true friend).
To not feel isolated friendship is something that will have to be done in meatspace. Take up a hobby or interest shared by others and participate in events or outings together. It will give you something in common to talk about and take the edge off striking up a conversation. Just becoming a regular at a busy coffee shop is a step in the right direction.
To me Meetup seems like a much more natural model. There's some activity I have an interest in and I can meet other people who also want to do it. The Bumble BFF thing like... OK, we have nothing in common except we want to make friends? Seems odd.