Hi Manon,
Welcome to Elvenar! There will be no wipe on the Beta server so any progress you make here, will remain in tact. However, should you make a new account on one of the live servers as soon as they're available, you will have to start all over again on that version. In that case your progress on this Beta version, will of course remain available here, so you'd have 2 games: One on this Beta server and one on the live server of your country.