Moving Website to wordpress

Im moving a website to wordpress. I already have an existing wordpress blog on the domain in a “/blog” folder sub directory. Im concerned with making sure I do the redirects from my existing .html pages to the new page I create with wordpress.

I read here

https://www.wordpressmax.com/customize-wordpress/custom-page

that I want to copy the .htaccess file from wordpress folder to the root folder. This will overwrite the .htaccess file that I have existing redirects and will need to set up many more new ones for the move

My wordpress htaccess looks like this

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /blog/
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]
</IfModule>

# END WordPress

My html website’s looks like this

ErrorDocument 404 /404page.html
RewriteEngine on
rewritecond %{http_host} ^example.com [nc]
rewriterule ^(.*)$ https://www.example.com/$1 [r=301,nc]

redirect 301 /products.html https://www.example.com/products/products.html

Would I combine these .htaccss file?

How?

If anyone understands what Im trying to do can shed some light on what Im doing and if there are any suggestions?

Thanks in advance