You cannot permanently set a specific view for a specific folder in in the default file manager of Ubuntu 18.04, Files. Files will not remember settings on a per-folder basis.
At the moment you have a folder open, you can set different views for that particular Files window. It won't affect other open windows.
Each time you open a new Files window, it will adopt the view settings of your most recent setting. With respect to the size of the window, it will default to the window size of the last closed window of the previous setting (i.e., close all windows, the size of the last one you closed is used next time you open a window.)