
In MuseScore, you have a bunch of tabs at the top, one of which being "Style". Through that, you'll get options of "General", "Text", "Load Style" and "Save Style".
You want to press "General". 
Here you can see a whole lot of options on the left-hand-side, but what we'll focus on first is the circled part.
Make sure this is NOT ticked. Otherwise the systems will be too far to the left for the instrument text (Piano and Pno.).

Now this is the biggest part. Under the "Page" tab, you have all of these options. By default, yours will look very different to the settings shown here. You can simply fiddle around with these until they match up with this image. You could also make it look however you want it to! It's up to you.

Finally, you can change the distribution of the measures using the "Increase/Decrease Stretch" function under "Layout". This is one of the most useful features for making a unique and visually appealing sheet. You can use the "Select" tool to select various parts of the sheet to stretch, or you can just select the whole sheet. Just remember that in a 4/4 piano arrangement there should be 2-4 measures in a single system.