Starting with web development , staying for the knowledge !

Hello everyone ,
I am happy to finally join blackhatworld . i'm currently learning web development and started exploring digital marketing .
The reputation of the community is the important thing that brought me here !
My goal is to make a strong foundation and avoid some common errors and improve day by day .
since i am just starting with web development , i would love to hear - are there any beginner mistakes that i should avoid and skills for beginners ?
Looking forward to learning from everyone .