For error no.4. you cannot have duplicate ids.
You can’t do this
<section class="main-section" id="Languages">
But also the id needs to match the text like this
<section class="main-section" id="Programming_overview">
You need to fix all of those id and make sure the text matches the id and the id has underscores like I just showed you.
For no.10 it looks like you are missing a section that was mentioned in the nav links.
It looks like this first one but you are going to have to double check that
<nav id="navbar" class="nav-link" name="navbar">
the text in the nav link class needs to be an exact match to the header text. The error message tells you one of them doesn’t match.
It tells you that one of the nav links does not have a href.
Go through each message slowly and double check that everything is matching.