Your question is somewhat general but here is an attempt to make it a little more clear and answer it.
copy core/themes/classy/templates/page.html.twig to your theme's template directory and name it page--front.html.twig and you can modify it as you like
but perhaps a better approach would be to do it in a modular way.
Find appropriate modules that give you desired functionality (slideshows etc) and most of them will allow you to create BLOCK(s) out of them and then you can add those blocks to any page you want but in your case it would be <front>.
So you front page could be made out of blocks from slideshow module and or views block(s) or even custom blocks (/block/add) or any other block.