YOu may lose your own status as a permanent resident if you are not residing in the US but residing in Europe.  Unless you have a reentry permit or spend most of your time in the US, you cannot retain your green card, as it requires you to be and to have intent to permanently reside in the US.  If you do not lose your status, you will be able to get married and petition your spouse for permanent residence in the US but in order to confer that benefit on your spouse immediately, you would need to be a US citizen.  As a green card holder, it can take a few years.  In the meantime, you spouse would only be able to reside in the US with you if he has his own nonimmigrant visa allowing him to do this.