Question: What does po tayo mean? I hear lots of Filipino Youtub

@tomas, = PO is a word use as respect to elders (grandpa,grandma, father , mother , uncle , aunt); to someone you meet for the first time;to someone who has a higher position than you (e.g. your boss, politician, etc.); also use to introduce yourself in public.
example:1. Kumusta po Ginoong Tomas ? How are you Mr Tomas ?
2. Ako po si Juan Dela Cruz . I am Juan Dela Cruz.While TAYO means WE in english.
Ako at ikaw ay mag asawa , YOu and I are husband and wife ; Tayo ay mag asawa, "We are husband and wife "

Thanks for reply, but the context I hear it, is on Youtube channels, when the host says "Po Tayo" to their viewers?

it means "we"(respectful) ex. 1.) "so may vlog po tayo ngayon "so today we have a vlog"2.) "eto na naman po tayo" - here we go againtayo - we (including the listener)
po - sign of respect

@pear Maraming salamat po