Fahai8

Hello community, I'm pretty new to the game and read about the method to evolve your Pokemon later to level them way faster. Now I have a few questions to this method: If I cancel the evolving, how can I evolve them later on? Do they need a stone or anything or do I get the chance to evolve them with every levelup? If I get the chance to evolve them every levelup, I should start evolving a 3 gen Pokemon from 98->99 and 99->100 or is it already to late https://vidmate.onl/ ?