A ride to Cabrillio Monument should be good. They make you pay to go all the way in I turn around at the pay gate. Go down to the SD River bike path into OB and head south
Ride around Mission bay
with the ebike I think your can extend your ride
Balboa Park to downtown and and the harbor loop can also get you to Cabrillio
Lots of ocean lots of views to be had depending how far you want to go or where you want to start from.