Natalie K.

I put together a quick video that can get you started but is by no means a comprehensive tutorial. I do go over using Add Noise and Levels.
 
 

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In the Affinity apps, a curve has a stroke width but a path doesn’t. If you draw a curve in Affinity Designer and fit text to it, the stroke disappears and you’re left with text on a path.
A ‘Curve’ object has only one pair of start and end nodes (which may be coincident) but a ‘Curves’ object has at least two pairs. For example, if you ‘Convert to Curves’ a letter O you get a ‘Curves’ object comprising an outer ring and an inner ring.

Hi, Natalie K,
Shapes in Affinity Designer are defined by a series of co-ordinates that are set down from the 1st to the last. This can be called a path, tho' the software will call both a sharp edged path and a smooth rounded shape a "curve." Or, in some cases "curves." 
One should not confuse these paths/curves with a mark on the screen. If one switches the view to outline, one will see a skeletal view. Nothing but a thin black line formed by the various nodes, which would appear if using the node tool on the object(s).
From this base, Designer can assign both a fill, and/or a stroke. Depending on what tool was used, and what parameters are activated, there may be either a solid plane shape which is only a fill, or a line that is just a stroke. Many users assume that seeing a stroke is a shape all by itself. It is not. It is only the stroke aspect of the shape, which has a start and end point whether those are joined, a closed shape, or unjoined, and open shape. On open path can appear as an unfinished perimeter. If one uses the "close path" widget while using the node tool, the 1st and last nodes will create a continuous perimeter.
Hope this clarifies.

If you type into Affinity designer help "Path' you get a better list than if you type 'Paths" Also search for Pen Tool and also Curves.
 
Also check out the tutorials linked in my sig that Affinity have created.

Thank you for clarifying the subject it was very helpful