“The fact that Mr. Carpenter was self-represented does not excuse his failure to comply with the necessary time limit or, once he was aware of the Final Order, to move promptly for an extension of time. Any participant in litigation, including a self-represented party, has a responsibility to familiarize himself or herself with the procedures relevant to the case: McDowell v. Cavan-Millbrook – North Monaghan (Municipality), 2016 ONCA 193, at paras. 20 and 21.”