As a person that's tone deaf and can't sing (yet I do anyway), I certainly can't give advice on how to improve your voice.
What I can say is, keep singing. If there are artists you want to sound like, imitate them. BUT, if it doesn't come natural then it's probably not for you. There are things you can tweek and they sound great. But, there are many things that are natural to certain artists, when people try to imitate them, it sounds forced and awful. Singers are not one size fits all. I knew a singer once who desperately wanted to sound like Paul Westerburg. So, he smoked none stop and drank till he slurred hoping for that raspy throaty sound. He never obtained it. He had his own unique sound, it just wasn't as good as Westerburg. But, seriously who is?
Keep singing. You'll find the voice and tone that fits you.