That depends on the level of antiquity.
If you are referring to a telephone with a rotary dial, you pick up the receiver, make sure you have a dial tone, then for each digit you stick your finger in the hole in the dial next to the digit, turn the dial clockwise until your finger hits the end stop, then remove your finger and wait for the dial to rotate counterclockwise (anticlockwise) until it returns to its original position.
Then there are the REALLY antique phones which I've never even seen except in old movies and TV shows. You remove the ear piece from its hook and turn the crank a couple of revolutions to ring the telephone operator. When the operator responds you tell her (it was almost always a her) the name or phone number you want, and she connects you.
Antique phone tables are available for purchase wherever fine furniture is sold. One can purchase an antique phone table from Horchow, Aliexpress, Wayfair and Amy Antoinette.
The phone number of the Antique Car Museum is: 509-779-4204.
The phone number of the Dougherty Antique Collection is: 303-776-2520.
The phone number of the Antique Boat Museum is: 315-686-4104.
The phone number of the Antique Cowboy Western Hero is: 417-766-0433.
The phone number of the Florida Antique Bucket Brigade is: 352-394-8709.
The phone number of the Hays Antique Truck Museum is: 530-666-1044.
The phone number of the Blue Mountain Antique Gas is: 610-588-6900.
The phone number of the Kyana Region Of The Antique Automobile is: 502-292-3235.
The phone number of the Westons Antique Apple Foundation is: 262-679-2862.
The phone number of the Antique Car Museum Of Iowa is: 319-354-3310.
The phone number of the Connectcut Antique Fire Apparatus A is: 860-623-4732.