remove vertices in blender I'm a beginner and I have a problem with merging vertices or removing them, I cant find remove by distance or I can't remove them with merge by distance.

It shows 0 vertices removed, if i increase the merge distance its happening like this.
Although, now, you can edit multiple objects simultaneously, you can't merge vertices between them. In this case, I suspect you will have to CtrlJ join the objects in Object Mode, before merging vertices in what would then be a single mesh.