The plant looks like Ambulia to me.
A 1.5 gallon is too small for white clouds. They're very active fish and need a larger tank. They will suffer in a 1.5 gallon.
Also, keep in mind you're definitely going to have to supplement the oto's diet with wafers or vegetables, since there won't be enough algae (or any algae) in that 1.5 gallon brand new tank.
Yeah I think it's probably a Hydrotriche hottoniiflora