Help fixing overlapping mesh

Just wondered if anyone is able to advise me on how to fix these self-intersecting edges/ faces?

Welcome @lawrencep

You’ll need to give a bit more information before people can help you.
How are you making this shape? What is it for?
Removing self intersections will involve changing the shape - what shape do you want it to be?

Sorry for the lack of detail! This is a zoomed-in screenshot of the top edge of a textured column /cylinder. The aim is to export this column as a .STL file so I need a valid closed mesh.
The lines where the mesh intersects on itself could become the new edges of the model.

It looks like it is an open surface with zero thickness - are you going to join it to another surface to make a solid? or do you want to thicken it by making a solid offset?

I ultimately want to use the capmesh command to create a ‘solid’