There are a lot of opportunities! Your teen just needs to get find a network. My DD (now 18) has been involved with the Young Feminist Party (formerly known as Generation Ratify) for three years. It was founded by youth to provide youth a voice in advancing the ERA and quickly expanded to be inclusive of gender justice.
They've got chapters nationwide in high schools and colleges. In addition to phone banking, they also provide training in how establish a new chapter, how testify in front of state legislative bodies, how to lobby elective officials and organizing rallies/marches.
If your teen does join, be prepared! The group really helped DD learn to direct her passion for equity. She has done all of what I just described above and is a frequent speaker/panelist. Yes, the girl who was uncomfortable asking the waiter for a new fork when she dropped hers is now comfortable speaking with anyone, anywhere, in any number. The Young Feminist Party has been fabulous!
https://www.instagram.com/youngfeministparty?igsh=MWwzZGczcHJrZzkyZA==