I feel like I've ruined myself by not using social media. Any tips?

Inb4 "reddit is social media." I know, but not in the same social, keep up with friends/family way.

I've been struggling with loneliness a lot lately, and have been making some small attempts at developing a social life. I'm 31M, live on my own in a small town. It is likely just coincidence, but a couple attempts at going outside my comfort zone have left me embarrassed and caught me off guard. I was wondering if anyone could give me some new perspectives or ideas, because I feel very much like an outcast.

I enjoy mountain biking/trail riding, and thought that a good way to meet some people would be to find a group to join in with. I searched online for any local meetups. All I could find were Facebook pages, but one of them had their next day/time listed. I showed up and there was a small group of riders getting ready, I introduced myself and asked if they were from the group I had found. They said yes, but they didn't know anyone was new coming because they didn't have any new signups. I told them I didn't have an account to sign up but I saw their next event listed and wanted to try and meet some people.

There was this awkward tone shift, and someone explained that they really preferred to vet new members before they let people join in. I just kind of nodded and said that I understood, 4 of the people went on ahead but two of the guys stayed and watched me while I put my bike away.

Back in October I was invited to a co-workers wedding. After the ceremonies, one of the photographers was loading up a bunch of heavy cases into her vehicle, so I asked if she would like an assist. We had a great conversation, and as she was leaving I gave her my phone number and she gave me her instagram profile.

She texted me a couple days later. She was surprised that I hadn't messaged her and said she couldn't find me online. I told her that I didn't have any profiles. She was very kind and understanding, but said she didn't feel comfortable meeting up with a guy without being able to read up on him first. That I could be creepy, or be married and trying to hide it, etc. I understood and thanked her for being honest with me. It still did hurt though.

Overall, it feels like I've shot myself in the foot by living offline. I haven't used social media (besides reddit) for almost 15 years, since I was still in high school. I have friends online and nice co-workers, but nobody actually in my life. I feel very stuck.