You’ll have to figure out how to take the extra stuff out of the CSV file – PowerShell won’t do that for you. One way is to use Get-Content to load the file, instead of Import-CSV; pipe the content to Select-Object and have that skip the first 2 rows (-Skip parameter), and pipe what’s left to ConvertFrom-CSV, and then to ConvertTo-HTML.
The HTML produced by ConvertTo-HTML is “clean.” That is, it doesn’t contain any formatting. You can use the -Head switch to insert an HTML STYLE section, which allows you to apply formatting. You’re going to have to learn some Cascading Style Sheet (CSS) language. You might also look into “Creating HTML Reports in PowerShell” (click the Newsletter tab here, it’s a free ebook on that page). I wrote a module that makes it a bit easier to apply more detailed formatting, and the book explains a bit of CSS. But there’s no way around knowing some CSS if you want to apply formatting. You should also know that most email clients don’t support the full range of formatting CSS can offer, so you’ll need to experiment a bit until you find something you like that also works. w3schools.com has a lot of good CSS tutorials and references, and that ebook is a starting point.