

This is maybe not what some would consider great advice but “you aren’t ready for a relationship” isn’t really fair. As you said:
But how do I get matured?
For me, a vital part of growing as a person has been experiencing the messiness of life. Failing and learning.
I’ve known the situation you described - planning things with someone you have a real interest in, someone who seemed interested in spending time with you. Placing high importance on the event in your mind only to have the event fall apart because it wasn’t a priority for them. Feeling upset and even jealous. I told her I was upset that she blew me off. It did not go well and she lost interest. That’s not to say this will happen to you, but my experience helped teach me to regulate my interest and my expectations because I didn’t want that to happen again. I also became more mature.
Yes, you should try to find a few friends if you don’t have any. Making new ones is hard but it’s important. I’m not exactly neutotypical and socializing is not something I enjoy most of the time. Still, it’s something that has been valuable to me. It’s kind of like a lower stakes relationship. You like them and care about them - you want to be helpful, do right by them, etc. If you feel clueless about interpersonal relationships you should make friends.
When my previous long-term relationship ended, she was very social and her friend group had become my friend group. I’d only had a few of my own friends and they had moved away or we’d been growing apart. When things ended, I needed to find new friends so I know how hard it can be. I recommend you find something you enjoy, offline if you can, and do that thing with people who also like to do that thing. For me it was board games, video games, TTRPGs, climbing, and hiking. I don’t love all those things but I can get enough enjoyment out of them for it to be worth expending the social energy maybe twice a week, if I had the energy for it. Eventually, after doing this for a few years (while I was in my mid 30s), I found a few people I got along with pretty well. They are now my friends. As a plus, doing things with them is less socially draining and keeps me socially active to a degree.
Regarding romantic relationships, you’ll need be the judge of whether or not you are ready. I think it’s fair to give it a try as long as you can handle failure in a healthy way and don’t have abusive tendencies. Obviously, every single one of my past relationships didn’t work out and I don’t think there was a single one of them where I could not have done better. They fucking hurt like hell but that pain taught me a lot about relationships and about myself. It felt like the end of the world, but it wasn’t. No amount of advice or self reflection would have taught me those important lessons without the experience and the pain of losing the love of someone I cared so much about. As long as you can learn from your failure - forge yourself into a better person - I think you can be ready.
I’ve been in a romantic relationship now for several years. My previous relationship was longer but like all of my other relationships, the failure and lessons learned helped me to recognize and improve on some of my flaws. It also helped me to to better understand and communicate my own needs and priorities. It all helped to create a healthier foundation for my current relationship.
For me, it’s hard to say one or the other is worse. It might depend on circumstances. Is someone making a false claim of rape worse than someone raping someone, or worse than a child rapist, serial rapist, etc? In damage collectively done to all victims, quite possibly. However, the intention of the false witness isn’t usually to delegitimize the claims of other victims. It’s usually shortsited and desperate - a desire to avoid social consequences or to punish the accused. I suspect such false claims are also more common among a younger, naive, immature population. It’s fucked up and selfish, surely. As fucked up as feeling you have the right to use another person’s body for your own physical pleasure or to assert dominance or whatever shit goes through a rapists mind? I don’t know.
Frankly, I’ve never been the victim or perpetrator of either crime, nor have I even been in a situation where either crossed my mind. All I’m qualified to say is that I wish neither crimes would happen to anyone.