I'll be traveling in Europe and I'm planning on buying a local Sim card while I'm there . I want to know if I'll maintain my contacts on my device if I change the card.
No, there is no option to store contacts on SIM cards anymore. Your contacts should be synced to your Google account so they're available from any device signed in to your account.
If you need additional help or have more questions or details to share, please join the site so you can reply in this thread. See this link for instructions on how to join Android Central.