Consider: Aliens land on Earth, they are vaguely humanoid in shape and size, but there is no real way to communicate with them. They're social, curious and friendly, though, and try to get to know humans and interact with us the same way as cats do. By mirroring.
They follow humans around - not necessarily any specific ones, but just wandering wherever people go - and do human things with them. Or at least do their best to try. In gravely serious, intensely focused, but deeply confused silence, they join human activities with this air of "I don't understand what we're doing, or what this achieves, but we're doing it together now."
When there are people waiting at bus stops, one or two of the creatures will join the group, standing in wait. When the bus comes, they'll join the queue lining up inside, and once inside, turn their open palm into a light source and show it to the bus driver in the exact same way as the people showing their bus passes from their phones (the aliens' ability to shapeshift this way has raised theories that they may not be naturally as humanoid as they seem, they've just adopted the human shape to better interact with us), and then go find seats wherever, just like humans do.
They're not going anywhere in particular, nor are they capable of actually paying for their ride, but since there doesn't seem to be any force to stop them from this, people just have to accept their presence. If the bus is crowded, they'll stand just like people do - and sometimes when seated aliens see a human offer their seat to someone who is pregnant, disabled or elderly, they will unpromptedly get up and offer their own to the nearest standing human.
They go to churches, temples, grocery stores, libraries, wherever people go, and clearly try their best to do whatever people are doing. In temples and holy places, they will sometimes join hymns in their eerie, wordless howls, which follow no melody but stop when humans stop singing. They sit and stand where the people do, and copy the positions in which humans pray, and many places of worship don't just tolerate, but downright welcome them - no matter what these creatures are, do they not have the right to pray?
In the libraries they are silent, eerily wandering the hallways, picking up books at random and staring at the pages, turning the page this way or that every few minutes. They don't bother anyone much, once the librarians figured out how to make them put the books they pick up into the returns cart, instead of some random place in the shelves. Some of them seem to enjoy simply grabbing random books, and carrying the whole piles to the returns cart.
They don't understand why we do what we do. We don't understand why they do what they do. But we're now doing it together.