Even if your data doesn't include the z values needed for 3D analysis, you can still create a 3D visualisation to help understand how the features sit in the landscape. At this year's Scottish Conference I included this in a short tech session on 3D in ArcGIS Pro. As well as looking at the visual impact of forest blocks, I also took 2D data representing a wind farm in the Scottish Borders and created a 3D visualisation of the site. The full details for the steps involved are in the help but I thought I'd take you through some of the questions you need to consider.
Creating the scene
Starting with your 2D map, the quickest way is to use the Convert button on the VIEW ribbon. But if you are new to scenes it might be useful to start with a blank scene and work through the steps. From the INSERT ribbon use the drop-down options on New Map to create your scene. My fictional data is in Web Mercator so I have the choice of a global or local scene. If you are using British National Grid (or another support local projection) you will need to create a local scene. It also needs to be a local scene if you want to be able to navigate underground.
Your empty scene will show your default basemap with added lumpiness. The default elevation surface uses the global elevation service from ArcGIS Online. Right click on the scene to open it's properties and view the elevation settings:
If you have your own elevation data you can add this as an elevation surface. If you move your elevation to the top and keep the default one it will use your data where available and the global elevation elsewhere. This allows you want to benefit from local accuracy but still be able to view the wider area (beyond the extent your elevation data covers). The Elevation Surface properties also include a scaling factor for adding vertical exaggeration to your scene.
Adding your 2D layers
The quickest way to add feature data is to copy one (or more) layers from your 2D map and paste them into your scene (this saves having to set the symbology again). The data will be draped on the surface but the layers elevation properties allow you to change the feature behaviour from On the ground if needed. There is also the option to add a vertical offset - adding a small offset can be give the layer a more consistent draped appearance. For this example I want to represent the turbines as vertical features alongside the forest blocks so I use extrusion to get the view on the right:
I don't have data on the tree heights so the forest blocks are extruded by are a fixed value of 40m with the extrusion type as Base Height (the options are set in the APPEARENCE tab on the ribbon). Given a suitable attribute you can extrude individual features by different height, using the Extrusion Expression dialog. For the turbines the view is a simple extrusion of the location point. Given access to a suitable rule from CityEngine you can get a more realistic appearance - something I showed in a post about Pro 1.3.
Refining the view
If your features span significant changes in slope you might need to make some edits to remove visual inconsistencies (work with a copy of the data if you need to preserve your original geometries). For my access roads this was simply a case of inserting extra vertices where segments crossed dips, saddles or crests. For the forest blocks I needed to split the polygons along the line of valleys and ridges crests. In both cases I found it easier to make the edits in a 2D map synchronised with my scene. The image below shows the draping problems on the left and the result of the edits (in this case four polygon splits were applied):
Finally, if you need to share your visualisation the animation tools in Pro make it really easy to create a video fly through. The easy way to do this is to create a bookmarks for the key views that you want to include, add an animation (on the VIEW ribbon) and import your bookmarks. There are lots of options for refining the sections of the fly through, including turning layers on and off.