Can someone help me?

A numerical for loop iterates through numbers at an interval. For example,

for i=1,10 do
    print(i)
end

will print out 1 through 10. The default interval is 1.

for i=10,1,-1 do
    print(i)
end

will print out 10 through 1, where the interval is -1.

A while loop will evaluate a condition and repeat the code inside the loop while the condition holds true. A repeat loop will initially run the code inside the loop once, and repeat so long as the condition holds true. This is the same as a while loop except for the fact that it always runs through the loop once.

A generic for loop uses return values from a function, like pairs, ipairs, next, gmatch, or any other function that is meant to be used in a generic for loop. You can get a more detailed explanation of generic for here.