I figured it out! I just needed to use break.

num = []
Ms = []
def Fmmin(va):
    while va == 0:
        for n in range(2, number):
            if number % n == 0:
                va = n
                break
            if n == number - 1 and number - 1 % n != 0:
                va = '0'
    return va
def Fmmax(va):
    while va == 0:
        for n in range(number-1, 1, -1):
            if number % n == 0:
                va = n
                break
            if n == 2 and number % n != 0:
                va = '0'
    return va

for f in range(1,10000000):
    number = 452021 + f
    mmin = 0
    mmax = 0
    mmin = Fmmin(mmin)
    mmax = Fmmax(mmax)
    if int(mmax) > 0 and int(mmin) > 0:
        M = mmax + mmin
        if M % 7 == 3:
            num.append(number)
            Ms.append(M)
    if len(num) >= 5:
        break
print(Ms)
print(num)