Can I use more than one term in a search of this web site?

Yes, you can!

You can use any number of terms that you wish.  However, you should be aware that when there is more than a single search term, the website searches for content that use ANY of the terms in your search box.  For example, assume that you enter:

Breastfeeding Midwives

You will find any content on the website that uses either term.  So your search will find:
All articles about Breastfeeding and Midwives
All articles about Breastfeeding including those that have nothing to do with Midwives
All articles about Midwives including those that have nothing to do with Breastfeeding

In technical terms, the default logical operator is a disjunction, and the space between words is treated as a logical OR.

Note that when you add several terms to your search each may produce more articles found, and your set of found material may be unwieldy.