OK Please be careful and turn off the power to the stove first and make sure your earth connection is secure as that will save your life if the stove has a fault.
Most stoves/cookers are designed to share the load across 2 phases or "A"'s
when available. The "A"'s are usually joined together if only a single phase supply.
Does old cooker site have only 3 wires coming out of wall ?
If you connect only 1 "A" to red/active then only half of cooker...
Here's an educated guess;
Assuming only one light fitting!
1) Most likely terminal "common" would be active with active loop to other devices/switches (2 wires).
Terminal "2" being switch wire to light fitting (assuming only one light fitting).
2) Terminal "wavy line with an arrow...