One of the formative experiences of my undergraduate education in math was attending department math talks. These were usually aimed at general faculty members, so they went well over my head at the beginning. Still, I found the experience helpful at giving me a sense of vocabulary, snippets of ideas, and a sense of the diversity of areas of math. A bit like immersion language learning.
I have a student who I would like to encourage to attend similar talks, but we don't offer them where I am. Normally I'd send them to a nearby school to attend their math talks, but the pandemic leaves things quite uncertain at the moment. Are there any online general seminars I can point my student to?