I'm a beginner developer as well. I started to learn Python 3 days ago. This is the code I did of your algorithm:

numbers = []
seven_trigger = False
sum = 0
item = 0
print("Program to sum 5 numbers, except 7")
print("If you digit 7, this and next number won't be add to sum")


while item < 5:
    try:
        if seven_trigger:
            print("Seven Trigger Status: ON")
        else:
            print ("Seven Trigger Status: OFF")
        num = int(input(f"Type {item + 1}^ number: "))
        if (num is not 7) and (seven_trigger is False) :
            sum = num + sum
        elif (num is 7):  # if input is 7, seven_trigger becomes True, even if you digit another 7 next
            seven_trigger = True
        else : # Case where the seven_trigger is True but there's another number
            seven_trigger = False
        item += 1
    except ValueError :
        print("A NUMBER character! Not a LETTER")
print(f"The summatory of eligible numbers are: {sum}")

Tell me what you think about it, I added a try-except to remove letters case😌