Preface: I'm a Christian, so this will be about the Christian view on things. I can't really speak for other religions, since I don't really know enough about them.
On prayer: asking for miracles is not actually the main point of prayer, the main parts are listening to God, and God listening to you. Imagine a perfect parent/child relationship. Sure, there will be the occasional "hey dad, I need some money to make this month's rent. Can you help please?" or similar conversation, but most of the time it will be the child learning from the wisdom of the parent, or the parent helping the child vent. If you want to see an example of what Christianity says is the sort of things to pray, look at the book of Psalms in the bible.
On other religions: yes, of course at least most religions are fake. A false religion could be started by someone who believes they heard from God but got it wrong, or someone who wants to be the head of a religion for their own gain. Many religions warn about false prophets, so this is hardly a surprising thing.