Meiosis and fertilization (Grade 10)

Hi guys. I'm new to the forums and I really need help and would appreciate it a lot if someone could help me out here. Well as you can see in the title the problem is about Meiosis. Now I have been searching everywhere and there are many mixed answers. so my main questions is that when they say the mother chromosomes and father chromosomes share each other is this after or before fertilization, because logically that would make no sense if it were before(how would they get the father and the mother chromosomes together, unless intercourse took place, which then leads me to believe this happens when the sperm cell meets the egg. However, that is not the case because it is the production of the EGG and SPERM cells, but how can sperm cells contain mom and dad chromosomes if nothing was exchanged?? ). Also there is a quite high chance that what im saying right now is completely wrong... So feel free to tell me I'm totally wrong and if you could take me through it step by step I'd be forever in your gratitude. Thanks