You may just start with using a simple roundish object.. here i'm using no ref .. ( bad ! ..and the back and lower part has to be tweaked a lot more..) and ( in blender ) subdivide with two cuts and smoothness one (and not the base two subdivision nor mirror modifier but symetrical edit) to specificly only modeling the a…
you might want to try something like this: this will you give you (most likely) some pinching on that top edge, but depending on what it is that thing, perhaps you can get away with it.
Prutsirs_JayJay you can search on Google, Youtube and even here at Polycount forum about them. There are a ton of info about constraints. Also you can check the "User Guide" of the software you use to learn about it. Hope you find what you need!