I dnt understand the for loops please help

Answer 1

for loop lets you repeat a set of instructions for a number of times that you can define in the for(arguments).
in the example below
for(int x=0; x<3; x++){cout<<x}
the for loop in the above example runs every time x is less than 3 then increases x by one.
the for loop will output the value x 3 times.
the first time x = 0 and the foor loop runs
x increases by 1 (x++)
the second time x=1 and the for loop runs
x increases by 1 (x++)
the third time x=2 and the for loop runs
x increases by 1 (x++)
now x=3 and the for loop doesn't run anymore because the condition x<3 is not met.

EDIT: my bad I didn't notice the question was "python" tagged.
more or less same principles apply.

Answer 2

for <x> in <collection>
(do something with x)

x = whatever you want the name of the variable to be, I tend to use item as the name and if number just x
collection = array of values or range of numbers

basically for runs through the collections values and on every round signes x as the value in that position on the collection.

hope this helps