These questions are in no way stupid, they are actually very important. So Im going to address the each in turn.
1. are there such rituals in the Pagan community?
Yes, as a matter of fact, almost all Catholic rituals are based on early Pagan ones. All of the Holidays you are familiar with, yes even Christmas, were taken over and based on pagan holidays. The early church attempted to get people to join their church but could not dissuade them from their pagan beliefs. So the Church decided the only way to convert the pagans was to copy their holidays and have them at the same time, to make it comfortable enough to convert. There is a lot of info about this on the net and I will post some leads to some of it soon.
2. If I became a Pagan at some point, does that mean I do not believe in
God or could not believe in God?
Absolutely not! All Pagans, are Pagan because they believe so strongly in a "God" life force. Now each one has there own interpretation of that force, does it include the Christian Dogma of Jehovah Elohim? For some, yes! For some, no, some believe in multiple Gods, some believe, as I do, that there is a "force" of some kind that created us, but choose not to label it and try to cram its essence into a human like shell. the beauty of Paganism, is the freedom to choose what you believe. There is no right or wrong answer, its what is in your heart that matters. And if you live your life according to what your spirit tells you, your on the right path.
3. Do you believe in life after death?
Absolutely! Most Pagans, same as above, believe with all their hearst in an after-life. It may not be what you have been taught, Most dont believe in the concept of the Christian Heaven or Hell, but many are student of multiple cultures and have come to accept the idea that our souls are eternal. Now what happens after our human life is done, is open to debate. As it has always been. There is no correct answer, the fact is no one has proof, we have only faith, dont we? Many if not most, pagans believe in re-incarnation. That they have been or will be reborn again to experience life and learn lessons for each one.
4. Keep asking! How else will you know, and think how many people are not brave enough to ask, be a voice for them.
Blessed be!