In ArcMap you could selct the properties and change the scale to change all the elements on the map to either be larger or smaller. Is that available somewhere in ArcPro?
On the layout tab of ArcMap you could rt click properties and change the reference scale so that all labels/symbols would change size and I can't find that in ArcPro.
Yes, this is available in Pro under the Map properties. You can change the reference scale by right clicking on your map in the layout, and selecting properties at the bottom. Then, in the general page you can change the reference scale.