Personal portfolio challange Feedback and issues solving

Hi all,
Nice to meet you guys!
I’m new in here, Just starting my coding yourney.
I would like to ask you for some help and feedback as well.
I’m having few issues on my Personal porfolio challange. First of all could someone give my any idea why navbar on my page isn’t fixed at the top? What I did wrong?
And second question is how can I make contacts form section and footer width same as page (full width)?

Page is here: