You can't change your true personality. You can learn about your personality, you can improve some traits, accept and learn to make a strength out of them. The alternative is acting, but not changing personalities completely.
For example, I am extremely quiet irl, it literally annoyed all people close to me, so I needed to improve in that and thanks to therapy I learned to talk more. I'm not talkative, but if the topic suits me and I'm in a good mood, I can be.
I am quite shy and introverted, but it allows me to be very observant, to listen and to understand people well. I also learned that I was happier with my 3-4 best friends playing board games and drinking coffee, rather than meeting a big group of people and having superficial conversations because I can't focus.
Being loud is annoying so don't be lol
About being funny, I guess you could try taking things less seriously in general, laugh at others who are funny, but don't force jokes yourself because if it's not natural it can come off as really fake and heavy.
Accept your personality, your flaws and qualities, and learn to appreciate them. You'll feel much better yourself and other people will like you more as well, the good people, believe me. It will show up eventually if you try being someone else.