Drawing complex shape in Blender 2.83 Well first I am a complete and utter noob in Blender, so treat me like a 5-year-old (and maybe I can learn faster, oh and take the piddle out of me :) with a nice bit of banter ).

I'm an artworker, and I'm getting into creating some 3D artwork in Blender and create some basic shapes with some small knowledge of blender, but I still cannot understand what a biezer or a node is or even spell it right. So that's my level in 3D. Give me Photoshop/Illustrator/InDesign any day.

I can draw perfectly in Adobe Illustrator and save an SVG file 1.1 from Illustrator (now this SVG file might not be the way to go) as you will see in the poor attempt below:



So as you can see above, a whole load of noise which I guess is because of the curve or SVG file (so pointer number 1 from you geniuses for a fix or best way forward - with details on how to draw/fix this shape in blender 2.8X) EDIT Subsurface Modifier did the weird stripes.

The next thing is... how the hell you put a cap on this thing, I've tried 'Solidifier' with a minus number in to fill it in, but that is obviously not the way to go.

This screenshot below is the blender layout mode... yes it looks nice doesn't it, with its nice curves and oh so innocent look... but when I render it, the devil is within.



I've gone through so many video's, tutorials and google searches I'm now calling on 'Tech Support' aka StackExchange.
I'm not sure I understand the question, but I'll take a stab at it anyway, and you can let me know how close I came. If you want, of course.

It seems there are two questions: 1) How to render without strange artifacts, (or just how to model this form best in general) and 2) How to fill in the top-most open face of an object like the one you have shown. 

This is my best guess as to what you are wanting to know. If I'm wrong, I apologize, but this is what I'm going to focus on until I know for sure.

Regarding 1): I'm still weak when it comes to rendering advice, but I do know that clean geometry is the starting point for getting renders to look right. There are many other factors, of course, but  geometry is the starting point, and that's something I know a little bit about. So you want to start with clean geometry. This leads us into a discussion about how to model your form.

Given the uniformity of it and the vertical nature of it, I would simply draw a top-view of the entire shape using curves. But then you will want to convert those curves to a mesh object before extruding it upward. Mesh objects and curve objects can be converted back and forth between one another using the Object Menu at the top of the 3D-View while in Object Mode. 



After the conversion from curve to mesh, go into Edit Mode to extrude the shape upward. As for the fill, choose to select by Edges with the Number 2 key, and then hold Alt while selecting any one of the top most edges of the shape in order to select the entire top-most edge loop. Then press the 'f' key to fill in the top side of the shape.

One final note: Rather than start all over modeling this, it might be better to select a single edge loop while in Edit Mode, using Shift-D to duplicate that edge loop, pressing 'p' to bring up the Separate menu, and then separate by selection. This will make the edge loop its own independent mesh object. You could then attempt your extrusion beginning from this new mesh object, rather than modeling a whole new curve object and converting it. 

The purpose of this whole procedure, by the way, is to test your results to see if they still have the artifact weirdness from earlier. If not, then this means you have created a repaired version of your mesh by following these steps.