I want to be supportive but this doesn't look like it was made by someone who knows anything about design. It's a great example of why 'studying design' is a thing. It looks like a Tardis/Dunkin Donuts Man/a big pair of shorts/eyes like black holes with half satelite dishes around them...none of the line weights mean anything, add nothing, and make no sense, color theory knowledge is zero, that's why the wrong things pop and also look awful together.

OP I think you need to work with someone else if you are going to produce a sticker anyone wants to look at. Do you like looking at this?

If you are just starting out as an artist, I don't want to discourage you, you can become one if you do the work and learn the skills.