Trying to program an anti cheat dll and have some questions

[SliderMan]

hello all.
i am trying to program a anti cheat dll for a game i am playing online with friends,
i thogut about making a crc function to check the memory of the game for changes
i know crc functions looks like:

DWORD CalculateCrc(LPBYTE lpData, SIZE_T dwSizeOfData)
{
    int i;
    DWORD dwCrc = 0;

    for (i = 0; i < dwSizeOfData; i++)
    {
        dwCrc += *(lpData + i) * (0x3e & 0x83)
    }
    return dwCrc;
}

now my question is, how do i read the memory from the game, just call a loop to every memory adress on the function. or should i make a tmp file with the memory and load it to the crc function?

also how can i determine what dll`s are loaded into a process?
and how do i check if debug registeres where used since crc hash wont change for debug registers. (as much asi know)


thanks in advance.

EDIT: could someone please help me?
any tip/exemple would be highly aprociated.

thanks in advance.
-Moshe