It's an electric guitar.
When I tighten the head of each string, it feels tight. However, the strings still feel a bit loose.
We can ask 100 questions and maybe never help you because you might not have the vocabulary to describe what's happening.
At some point you'll need to have someone who knows about guitars try it. Or maybe you can look closely yourself and figure it out.
If you aren't tuning it to pitch you'd get one set of problems.
If you are tuned to pitch and aren't fretting it and it buzzes, that's a different set of problems.
If you ARE fretting it and it buzzes it could be the same or additional problems.
If it's all the strings buzzing, that's a different situation than just one string buzzing.
Please help us help you by narrowing things down.