Can a stray/community cat become an indoor cat?

Hi everyone. I want to start off by saying I don’t know the first thing about cats as I’ve only ever owned a dog. I’m looking for advice or considerations for this situation I find myself in.

A stray community cat has become very friendly with me. I’ve been living in this apartment complex for almost 3 years and from what I’ve noticed, he’s always been in the neighborhood. Several people on the block leave food out for all the strays, including him. About six months, this male cat started coming on walks with me and my little dog (and this cat was always very sweet towards my dog). Then he started hanging out around my doorstep often. He’d let me pet him and sometimes I’d just hang out on the doorstep with him. I ended up putting a cat shelter outside for him when winter came because I was worried he’d be cold just sleeping on the doorstep and he never liked the blankets I’d leave out in the past winters. He uses his shelter now. I’ve started feeding him because he seems hungry and meows at me. Lately he’s been forcing himself into my living room, and I cave because he seems to want to hang out. I’m conflicted with how invested I’ve gotten and also with what’s best for the cat.

My little dog passed away last month so the last thing I wanted to do was take on another pet as it’s a huge commitment and responsibility. I’m also heartbroken in my grief. (On a side note, I have a camera at my doorstep and I was able to see this cat unexpectedly showed up at my doorstep the literal moment my dog passed away so think what you want about that). truthfully, I’m very nervous about the thought of taking in a cat because I’m ignorant to what that would look like. I feel like this cat has wiggled his way into my space and I never intended to let that happen. But I’m a sucker so it probably didn’t take much. He’s a very sweet boy…

Do stray cats often behave this way with humans?

Is it possible for him to prefer or be happy indoors after being outdoors 24/7?

I’m trying to figure out what’s the best thing for him. If I decided to adopt him, I would not want him to roam outdoors anymore. But I worry that he’d be unhappy as an indoors only cat. I also cannot have more than one pet in my apartment so getting him a buddy is out of the question. I feel like I’m going back and forth between what the “right” thing to do here is.

What are the things to consider when taking in a stray to become a house cat?

What does being a cat owner look like?

How does one be a good cat mom? I have no doubt I’m a good dog mom, and I really do just love all animals, but a cat is an animal that I never considered I’d own/take in.

I’m intimidated by this, can you tell? If anyone can give me thoughts, opinions, suggestions, I’m all ears. At the least, thanks for reading this to the end if you made it here.