Acompañar a
 

Voy a acompañar a papá al centro.

Can it also be:

Le voy a acompañar a papá al centro.

And

¿Tú llamaste a Pablo ayer?

¿Tú le llamaste a Pablo ayer?

Thanks!

The verb acompañar takes a direct object. If the direct object is a person, a personal 'a' precedes it.
You should not introduce an indirect object pronoun, since there isn't an indirect object.

The same goes for the verb llamar.

Muchas gracias!

I just noticed something.
You were essentially asking if it's OK to introduce a redundant pronoun that references the direct object. This is certainly allowed.

When the verb takes a direct object, using the pronoun 'le,' instead of 'lo,' is called leísmo. This is allowed in certain regions, especially when the direct object is a male.

I'm sorry I didn't mention this earlier.

So, if I got it right the above sentences with le are correct. Is that right? Or should I omit the le because these certain verbes (acompañar- llamar) never take an indirect object?

The direct object in your first sentence is 'a papá' (the preposition 'a' is necessary when the direct object is a person).
It is OK to add a direct object pronoun to your sentence (it is redundant, because the direct object itself is present, but many people will use a redundant object pronoun).

The direct object pronoun for a male is 'lo'.
However, in some parts of the world, the indirect object pronoun 'le' is used instead. This is how they speak in some parts of the world, and the academy of the Spanish language accepts this usage (calling it leísmo). If you're in an area where leísmo is common, it's OK to substitute 'le'. Otherwise, you would use the direct object pronoun 'lo' (if a redundant object pronoun is desired).

Use the direct object pronoun 'la' if the direct object is a female.
In areas where leísmo is common, the people will most likely say 'la' in this case.

I first explained how using an indirect object pronoun would be improper, since there is no indirect object, but it is perfectly OK to use it in some parts of the world.

You've been very helpful. Thank you very much!