Should a father sit in the front left or front right?

At the ones I have went to, at a funeral the mother and father sit on the right side ( if there are sides, not all funeral homes have sides. ** assuming you mean which side of the middle isle ?

If you are talking about mother sitting to the right or left of the father, the mother often sits to the right of the husband.

But to be honest, the funeral home will direct the family where to sit, and as to mother and father, where they sit is often not the issue they are worried about and it is not a concern to anyone.