Hot water recovery rates are lower with electric (and you can't tell when its up to temp as easily as when the gas shuts off) so the time from initial fill to full hot will be longer.
Also check your winterizing valves at the back of the WH - you should have been shown where these are during the walkthrough. All trailers shipped to locations where where winters go below freezing are shipped winterized (they can't tell how long its going to sit on a dealer's lot). In winterize position, the oval handle on the bypass valve (the one that runs between the hot and cold) is in-line with the pipe (and the hot and cold on the individual lines closer to the WH are perpendicular). In operating position they should all be 90 degrees from that. Leaving the bypass in winterize mode is a common issue causing lukewarm (or variable temp) water for newbies with new trailers.
2015 Rockwood Signature UltraLite 8282WS Platinum, GY Marathon LRD, TST 507RV TPMS
2005 GMC 2500HD CCSB D/A, Curt E16, Prodigy P2, Garmin RV760LMT w/BC-20 b/u cam