Help: Solidifying Circle

I need help solidifying mesh circles. I am designing some stuff and am new to blender (I used to use Autodesk Inventor).

somebody help please?

Solidify in what way ? Show us exactly what you have and what you want

If you want something like torus, either just add a torus primitive or use a curve circle and in the curve settings set the ‘Fill’ to Full and increase the bevel depth and bevel resolution settings