How can I add in remove, second enumerate, random, and validation to my current code? [on hold]

guest_list = []

while True:
    guest = input('Enter the name of each guest and press enter to stop adding guests: ')
    if guest:
        if guest in guest_list:
            print('That guest is already in the list')
        else:
            guest_list.append(guest)
    else:
        break
for index, guest in enumerate(guest_list):
    print(f'{index + 1}: {guest}')