Some vertices of your mesh are going over the Y axis. Just a bit, but enough to cause a crease.
Select your whole edge
Scale it to 0 along the X axis (so it's flat)
Move it precisely to the Y axis.
(This is the fast solution, you can of course move the vertices one by one.)
This is my personal view, based on my own experience, so some others may see things differently: Sculpting from scratch is possible, but works best with purely organic forms which don't have a lot of lengthy or technical structural features. If they do have these, then it can be expedient, I believe, to begin with a modeling process instead of a sculpting ...
This is the Fast Navigate option.
For multiresolution models, shows low resolution while navigating in the viewport.
It is a viewport optimization, which is useful if your high poly model is slowing down Blender. To disable it, go to the Tool Options in sculpt mode, then navigate to the Options section and disable Fast Navigate.
I've noticed many people having problems with their tablet pressure sensitivity not working in Blender but working in other programs. I had the same problem and the solution was quite unusual. My graphics tablet (Huion Q11k) stopped working as soon as Blender lauches, unless I activate game mode. Game mode disables pressure sensitivity. The fix for me was ...
The sculpt tools operate on the existing vertices in the mesh, so in your case, they can only move around the 8 vertices that exist on the default cube.
Either subdivide the cube to add more vertices or enable Dyntopo which adds additional vertices as you sculpt to show the details.
Yes,it can be done. But probably what prevents you to do so is: there's already another "shortcut" using the same combination in Sculpt, by default.
if you search for "sculpt" in preferences, you'll see that there are three different mouse/keyboard combinations to do the "sculpt" action, including this:
you can remove it by clicking on the "x" icon right ...
There might be a new way to paint in 2.8 but for the moment your object doesn't have any material, so create a basic node chain like Image Texture (with your "main Okulossos Paint" image loaded) > Base Color input of a Principled BSDF > Material Output.
Now you still won't be able to paint, it's because you've opened a completely black texture for your ...
You have basically two options to go from here but keep in mind that both of them (and sculpting in general) are destructive meaning they're irreversible. So if you like your low-poly mesh it would be smart to make a fallback-copy of it (Shift+D) and put it in a separate collection that you can hide, so it doesn't bother you during sculpting.
With that ...
You're using modifiers: Mirror and Subdivision Surface.
Blenders modifiers get applied after the geometry is evaluated. This means your only sculpting on this very low poly mesh even though you can see the result of the modifiers.
Apply the modifiers first if you want to sculpt on their generated geometry.
I was able to sculpt when I applied the two modifiers (mirror & sub) and filled the holes in Edit Mode (select all + f for fill). I don't know enough about the sculpt tools but maybe brushes like crease need closed meshes. Depending on what you want to do don't expect high resolution and details without Dyntopo on this one.
The Unified Brush settings have been moved from the menu to "Properties - Tool Settings".
You find them on the right side of the Radius and Strength settings, represented by a globe icon.
To access them more quickly, you can always add them to your Quick Favorites Menu (RMB - "Add to Quick Favorites Menu").
I found the answer with Blender version 2.83. There's a new feature called Face Sets, when remeshing you can tick the box to preserve the face sets in tool layer > Remesh.
But you have to make sure you ticked off "Dyntopo" before, or you won't be able to remesh.
You could duplicate your object, sculpt on the copy with Dyntopo, then bake the result on the original object.
Another method is to use the Multiresolution modifier then bake the result on the same object as explained here by PIXXO 3D. It works fine with 2.79, not with my version of 2.8 but it may have improved since.
Subdivide your object a bit. Shade ...
You need to put your mouse as on the picture below (on this narrow black line between viewport and editor type) and right click:
than you can choose between horizontal or vertical split and left click on the place where you want to split your viewport
now you can scuplt in both areas :)
You can add detail until you get to a point where its so small your computer struggles, or you'd rather just let a texture handle it. Maybe large wrinkles or veins I'd sculpt, and the rest I do with a brush template or while texturing. Certainly around the eye I'd sculpt wrinkles and detail, as no way that can be simply covered by a brush or texture. ...
You can sculpt more than one object but you need to make sure to uncheck the option Lock Object Modes, letting you select each and switch to sculpt mode.
You will still need to select the object you want to sculpt, but they will both be possible to sculpt without going back to Object mode for each.
If you want to sculpt both objects without needing to ...
The center colored dot snaps to the nearest vertex and also appears on the other side of the model if you have mirroring turned on, as Yohello said. As far as I can tell, the outer circle shows the size of the brush, and the inner circle represents the strength / falloff of the brush, and increases in size as you increase the brush strength.
If you want to ...
1) you have enabled symmetry, the dot on left indicates where the symmetry of your brush will apply.
2) the inner circle indicates strength of the brush. You can change size of your brush by pressing F, when you pres SHIFT+F you can adjust your strength.