It soulnds like you don't have any clue.
You don't have "two red lives"
You have one red live from the lighting ring and one red switched feed to the existing lamp.
The neutral (or retuirn) connection to the lighting ring for the existing lamp is in the ceiling rose.
The new lamp would need a link from the live feed from the lighting ring, to one side of its switch and a new switched live feed to the new lamp.
The neutral (or retuirn) connection to the lighting ring for the new lamp would probably have to pick up the connection in the existing ceiling rose.
It really sounds like you have no idea.
SERIOUSLY: Get a qualified electrician in before you kill yourself (admittedly inconvenient for you but useful to the human race as it will remove stupid genes from the gene pool) or someone else (much worse)