You have a hosting account with hosting credits. You are charged one hosting credit per day.
do we have to pay 10 points a year for hosting or is it just pay 10 points and you get hosting?
This means that, if you have 30 points, you may stay one month without posting. But you will see your hosting credits decrease, having one credit less every day.
When your hosting credits start being negative, you will have to add credits until your credit turn back to positive.