After school and until 1995 Gero served basic military service in the 6th Armored Infantry Battalion in Schwanewede; from 1995 to 1998 he took a training as a bank clerk at Sparkasse Bremen, then worked in marketing; and studied economics at the University of Bremen from 1998 to 2003. During his studies, Gero absolved several international internships in New York, Canton (China) and Adelaide (Australia).

Until 2006 he worked as an investment advisor at Nordwestfinanz Bremen; then from 2006 to 2007 as a research assistant at the Institute for Institutional Economics and Innovation Economics at the University of Bremen with research stays in Alabama and Oregon and got his doctorate in economics. From 2007 to 2008 he became assistant to the board of management; and until 2009 sales manager at Allianz Beratungs- und Vertriebs-AG in Oldenburg.

On October 28, 2009 Gero entered into the state parliament, as a member of the Lower Saxony state parliament of the 16th and 17th legislative periods;  and then became spokesman for environment and energy as well as chairman of the FDP district association Elbe-Weser.

Since 2017, he is a member of the German Bundestag since 2017 and spokesman for agriculture and nutrition for the FDP parliamentary group.