creating a plastic box

Can anyone tell me how to create a box like structure open at the top in Creality Print 5.1
The only way I’ve been able to do this is to create a cube, hollow it and them split the top off. Sometimes it works sometimes not. New at this game.
In Tinkercad you can create the box and then create a hole slightly smaller then group them.
Also impossible to form a blind hole and a square hole is never oriented the right way.
Thanks for any help.

Should be easy on a CAD package, I don’t know TinkerCAD, I know I can do this in minutes on Inventor and probably Fusion360. This is less about Creality Print and more about CAD design skills, practice makes perfect as they say (I’ve been practicing CAD for nearly 40 years and I’m still not perfect). The grouping of holes is often referred to as an array, This can be a rectangular or circular array or an array made out of points defined in a sketch (yes I am boring at dinner parties)

If look at my second post on the subject you will see that I eventually solved it. In creality you don’t see the result until you slice it whereas Tinkercad you can see it as soon as you group it