Hi,
I have a situation where there seems to be air in my cold water pipes.
When I get up in the morning and flush the toilet, or run the cold
water in the sink, the water burps and carries on. After about a
toilet refill's worth of water, the situation goes away until the next
morning. My neighbor says he doesn't have this happening at his house,
so it doesn't seem to be the outdoor pipes.

Does anyone have an idea of what is happening or at least what to look
for?

Also, is this just annoying? Or, could it damage the toilet internals
(or any other appliances)?

Thanks in advance.