How do I design a through-hole pad in Altium Designer?
When you design your schematic component, assign Designators to the pins, e.g. A + B or 1 + 2, .... 
In your PCB Library item (the one that is linked to your schematic symbol) use the Place -> Pad, select "Multi-Layer" as Layer, enter a hole size (.7mm) and a pad size (e.g 1.5x1.5mm) and you're done, name the two pads A + B (same name as in the schematic).





Now when you transfer your schematic design to your PCB, Altium will assign the appropriate nets to your pads.