Hi Lucien, God bless you for following your vocation! I will reflect the above and say that you should ask these questions to the Monastery itself - try ask them to whoever has given you the "yes" towards discerning with them. I'll try to answer your questions generally in the meantime, though it won't be of much help as you shall see!
[quote="lucien123, post:1, topic:271646"]
1) First of all, should I pay them something (like a donation) for staying with them? (money is not something I have much of). Please advise.
Pay - not unless they have asked you and have made it clear that you must pay.
Donate - possibly, if you can.
If this situation is you going into the monastery to test a vocation, they probably will not be expecting any kind of money. If they do ask for something, explain to them your current financial situation.
2) Will I have duties during this time? If so, any idea what they might be?
Quite possibly you may. It all depends on what kind of retreat they have planned for you. Carthusians are very contemplative, hermit monks so you may very well have a week of silent retreat with spiritual direction, reading and odd jobs like washing dishes and helping the lay brothers. Perhaps not. Who can say? You will have to wait and see!
3) What Items should I take with me? Clothes, rosary, bible. Anything missing from the list?
Clothes to sleep, clothes to do labor in, and clothes for the chapel would probably cover your clothing. Rosary, of course. Bible yes but they probably have many. Missal if you have one. Toothbrush, perhaps a torch depending on their monastery. I wouldn't worry too much about what to take in terms of physical things!
3) I attend church regularly, I know the bible well, I pray the rosary etc. But I'm not very knowledgeable with saints and stuff like that. Will this be a problem in any way?
Certainly not. You are there to test if God is calling you to His glorious household to be His servant. You're not there to get a diploma :D All you need to do is have an open heart and a love of Jesus Christ. What is the use of knowing 1000 saints if one does not seek the will of God? Don't worry about what you do or don't know about this or that. Whatever happens, you will learn what is necessary in due time.
I'd Really appreciate some advise on these things.
Hopefully that helped a bit. I suppose you will just have to wait and see. In the meantime, don't focus too much on what you will have to do or what it will be like or small details. Just live everyday dedicated to God - live today as if you were in the monastery as much as you can.Before you know it, you'll be in the monastery and discerning God's call.
God bless you in your vocation, I pray that God's will be done :)