Help with try, except, else finally

[jefsummers]

Also, if you see a lot of repetitive code (like here), take a step back to see how things can be combined - often in a function, but even easier here. Combining what has been stated here

#User inputs math type
operation = input('''
Please type in the math operation you would like to complete:
+ for addition
* for multiplication
''')
#User inputs number

while True:
    number_str = input('Enter your numbers, separate by comma: ')
    try: 
        numbersstrings = number_str.split(sep=',')
        n1 = float(numbersstrings[0])
        n2 = float(numbersstrings[1])
    except Exception:
        print("You have not followed instructions!")
        continue
    break
     
print(f'{n1} {operation} {n2}')
if operation == '*':
    print(n1*n2)
if operation == "+":
    print(n1+n2)

Now this still is not great - I agree with Dean that you should allow the user to enter the operation at the same time as the numbers, but this illustrates a number of items/learning points -
The while loop that goes back until the user enters properly formatted numbers
The use of break and continue
The use of f strings rather than .format
Minimizing repetitious code