Even having a burner phone without any personal information on it can be deemed suspicious. It would be best for your phone to have a recently-reinstalled OS, with a few critical apps like Whatsapp or iMessage set up with a few personal messages sent. You need to be able to set those up without a password manager. Anything else needs to take place on devices that you aren't carrying with you. Fortunately enough people don't update their Facebook these days that just having an account that exists but you don't use will probably work, assuming you don't look like someone that would be obsessed with their socials.
Maybe there are USB thumb drives that operate like a YubiKey unless special setup is performed to access the storage inside? That's one way to carry data with you if you have to.