Fortunately, you do not have to do huge simulations to get the basic design information on directional couplers.
Before even you use Microwave Office, look at **broken link removed**
Then in Microwave Office, look for Open->Examples, and offer the keyword "coupler".
You will find various couplers directional, even though the word "directional" may not be there.
e.g. the "Lange" type is a directional coupler.
If it is layout planar type, then there are edge-coupled microstrip lines as MWO components.
Hint: Keep in mind that making a directional design in microstrip, and including a topside dielectric layer or even a layer a with floating topside "groundplane", (a bit like sort-of stripline), can have a good effect in equalizing the odd-mode and even-mode impedances. A floating top dielectric over the coupled regions can give a better performing coupler. This is stuff I came across long ago, but take care.. you need to simulate carefully to get this right!
MWO and it's layout are devoted to EM simulation, not especially to manufacture layout. Therefore the process of setting up the drawing layers, and exporting layout information (Gerber or IGES etc) to get it made is somewhat awkward, to the point that if you have the layout dimensions, you might want enter them in a straightforward PCB layout tool like Altium, or maybe the free one "Layout Editor" from Jurgen Thies.
Have a look at -->
https://www.layouteditor.net/