There are quotas for international students so make sure you check those for the fac you would like to apply to. Moreover, the PACES are extremely competitive (statistics vary but are in the range of 15%-20% depending on the university). As such you will really need to work very hard and even then you are not assured a place in second year.
The first year is commonly referred to as a concours or competition. There is a numerus clausus that is decided annually by a central authority and the cut-off points required to pass are determined accordingly. The majority of exams are multiple-choice questions and therefore require a lot of practice with these.
If you want to pass successfully, there are a number of strategies one can employ. My suggestion would be to join a prepa or preparatory school that will guide you throughout the year. These can be quite pricey but are known to be very helpful for those wanting to enter the second year.
