You'll never be a better person if you don't want to be a better person. This is the first real hurdle.
Self improvement takes a lot of time and focus. It's easy to lose sight of your goal, but there are ways to help with that.
If you want to succeed, you'll need the confidence to do so. You'll need to see your improvement, see what effect it's having, and celebrate the improvements.
A turning point in my life was discovering an old text file I'd created about 7 years before. It was a file titled 'Become Awesome.txt'.
That file was a list of things I wanted to do to become, in my eyes, awesome. Things like learning to program, learning to touch type, learning some form of dancing.
Before I found that file, I felt stuck, like I wasn't progressing. I felt like everything I tried to do failed.
That file showed me that I had not only met all my goals, I had exceeded them. I would have been awesome to my younger self. And now? If I could have seen where I was going I wouldn't have believed it.
Without discovering that file, I wouldn't have the perspective to see my progress. It is SO VALUABLE to see your progress. As such, I highly recommend setting yourself goals.
Write down what you want to improve about yourself. Write down your goals. You don't need to achieve all of them, and you shouldn't worry about how long they'll take, but do write them down.
When you make progress, make a note of it. It can be in the same document, or in a calendar. Any improvement at all, you should track.
An easy way to track things is if you create a group chat with trusted friends. They can support you and celebrate your wins with you.
When you start looking back at where you've come from, you'll focus less on the goals you've given up on, and start to notice the goals you've achieved. (And if you said 'I've not achieved any goals' there, then you, my friend, are exactly the person who should do this.)
When you're working on yourself, one big thing you'll do a lot of is self-discovery. This may include things such as hidden skills you didn't expect, differences between you and other people, or even that a goal you had is really not right for you.
Don't be afraid to change your goals as you progress. Maybe you wanted to learn to paint, but discovered that you lack certain artistic traits, and it stops being interesting to you. Maybe you wanted to get a girlfriend, but suddenly discover that you're more interested in men. Maybe you wanted to become an airline pilot, but discovered that you'd rather become a microlight tour guide.
Goals change over time, and when they change, it means you've improved to a point where you can see the goals more clearly.
These are good things, and things you can work with to better discover who you are.
When you change, you realign your brain, but it's not a fixed modification. If you're trying to be less angry for example, you may find yourself relapsing. The world is full of different stresses and problems which can trigger relapses.
What's important is that when you do make a mistake, you stop, you analyse what happened, and try and see how you can avoid making these mistakes again next time.
Sometimes you need more practise, sometimes you need to be more self aware, sometimes you just need to do things differently, but no matter what the answer is, when you get an aswer, you've improved. So making mistakes is a part of the process, and is entirely allowed.
If you are trying to make a change, you need people around you who will support that change. If your friends are always putting each other down for example, then they may not support you as you improve.
You don't need to get rid of your old friends if they're not actually holding you back, but do find new friends and groups. Your old friends may learn a thing or two as you improve and may become more supportive in time, just be sure not to let them get you down.
Your goals will likely be based on what you think is good and right. You need to be flexible to new ideas, and that may affect your goals.
If you believe that orange is the best colour in the universe and are working on changing your skin colour to orange, and someone says that blue is better, have a discussion with them about it. Listen to their arguments, and, if they turn out to be right, change your goals.
(Orange is actually a better skin colour than blue to have. Orange skin is gained from lots of sunlight or fake tan. There are a few health issues related to excessive sun exposure, and more related to fake tan chemicals, but argyria, or silver poisoning, which turns you blue, is less healthy.)