Help me improve my social awareness skills and manners to become a better friend

What is everything I should do when I invite and expose a friend to an event hosted by a new and different (friend) group?

For context:
I (21f) invited my girl (21f) to a lunch event hosted by an educational organization (that consists primarily of guys).
We all work and study in the tech field.

This is the first time she met them — and I failed to make her feel included.

I only realized my issue tonight when the president of the organization reached out to me and told me I should have introduced her to each member and I totally agree.

So the next time she joins us for a karaoke event, I will introduce her to each member of the organization.
What else should I to make her feel welcomed and included when we attend this upcoming event?

Seeking your help:
Please let me know how else I can make my friend(s) feel comfortable, welcomed, and included, when I invite them to social events (that have a lot of strangers or people they don’t know)