page of posts template Pagination not working

hello,
i have searched the whole forum for this issue and i couldn’t find a solution for this problem, although there is already a topic with this matter his code was way to complicated for me and i’m a newbie on wordpress, during my search on this forum i found this code solution on how to make a page of specific post template by catID, but no matter what i tried i couldn’t get the pagination to work where there is a lot of posts,
here is the complete code
please help me solve it (please don’t redirect me to a plugin since it took me a week to understand how to create this page of posts i just need help on fixing the code so pagination will work).
thanks
joe

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