French is indeed a Romance language, not a Germanic one. The Franks were a Germanic people and presumably spoke a Germanic language prior to migrating into Roman territory, but in France they came to adopt Latin as their language, and French is a descendant of that vernacular Latin, most closely related to Spanish and Portuguese (and other members of the Western Romance branch).
English and French are related only in that they are both Indo-European (one from the Germanic sub-family, the other from the Italic sub-family). However, of the external languages to affect English, French has had the deepest influence of any save Old Norse. Most of that French influence was lexical, though. As far as I know it had little if any effect on English grammar, and was not an important source of functional words.
Here's a great image if you want to see how all the Indo-European languages fit together:
Indo-European Language Family
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