It's true that through evidential mediumship folks here in this world may sometimes be able to communicate with family or friends 'over there'. But it's not like picking up a phone and there's no certain way of making contact with anyone let alone a specific individual. As indicated in other postings, your thoughts will reach your father but that's not what you were wanting.

Depending on where you are living it might be possible for you to find a Spiritualist medium or to visit a Spiritualist Church or centre. There you should see demonstrations of mediumship where folk receive messages from loved ones.

That will give you some appreciation of what can happen and there's always a chance you may receive a message yourself.