Together or not, make sure he knows how you feel about him. Distance cannot be an excuse and material goods are the least important.
If they live in different houses
1- Enjoy your free time and choose the photo that you like the most. Send it by e-mail in the morning, as if it were a virtual card.
2- Select any of the restaurants that are delivering or take-away and order a meal for his home.
3- Make a video call and talk to your dad.
4- Invent a virtual tour to pass the time, choose together a museum or opera to visit and comment on your favorite works or moments.
5- Watch a streaming music or movie show and chat at the end.
If they are in the same house
1- Prepare a breakfast in your special bed, either with a pastel de nata (learn how to make one here) or with homemade cinnamon cookies.
2- Make a manual gift with what you have at home, use your creativity.
3- Write a letter to him by hand.
4- If he is not working, spend the day with him, he will not have as many opportunities as this. If he has to work, make the most of his free time.
5- Before going to bed, have a conversation with your father. How long have you been talking to him like you are talking to your friends?