Don´t overthink it when it´s your first comic. Choose one simple style and try to stick to it without comparing it to other comics or trying to draw better than the simple style.
The best way to do it, in my opinion, is to first have a story idea, start, finish, middle.
Then do the characters, it helps me to know a lot of details about the character. Where
was he born, parents, relationships, every little detail you can imagine like he doesn´t
like classcial music and churches. Some of those things are maybe not important and
don´t have to play a role in the comic but those things help you to know your character
and the character gets allive in the best case and you know how the character reacts.
The character is grumpy and often mean, it´s easier to know why he is always grumpy
and then you know how he reacts in certain situations.
After the character descrition you can write the story. It will be way easier when
you know the people and can picture them in your head.
When the script is finished you can create character sheets for every character,
so you know how tall they are, what clothes they wear and you can check with
the character sheet when you draw the comic.
This is all just theory/ a tactic I try to use. I´m far from being good at this
