Hi just signed up as I am very new to blender and I have made something in object mode which I know want to make changes to in sculpting mode however nothing is happening when I try to use the sculpting tool. Has anyone got any solutions to this problem? Thanks for your time
Depends on what exactly it is you created. But, it sounds like you need more vertexes. I usually subdivide the object (in edit mode) to create more vertices.
Sculpted Cube[with extra subdivisions]
This is an example. But, more vertexes = more articulations (typically).
Of course what you need to do is subdivide to add more topology.
You can do this by adding a sinple subdivision modifier or subdividing in edit mode(as the other answers said), but one is irreversible and the other leaves out a lot of options.
The Best Way to do this
Multiresolution Modifier Under the modifiers tab, add a multiresolution modifier, click simple a couple of times. If you want your objet to be smoothed, then click subdivide instead. You can even click simple and then subdivide to create an object with only the corners smoothed. You can set a different resolution for sculpt, viewport and render.