Hi Sarah,
Using a 'quick install' for WordPress is fine.
The manual install does the same thing, just takes longer, and is a bit more complicated for new users.
Things like passwords to the SQL database will be super secure using the quick install.
Make sure you use a random password generated password for your admin login to the site as well.
If you're worried about security make sure you use a good WordPress security plugin like WordFence.
You can also get a cheap SSL certificate for the site from
https://www.ssls.com/ssl-certificate...do-positivessl