@Xuebit If you have experience with PHP, that could save you some trouble. A lot of plugins are just replacing what could be a single function in your theme's functions.php file with the same single function, plus a bunch of extraneous features you didn't ask for, plus some weird terrible interface shoehorned into your wp-admin. If so, WordPress works in a way that is unique, and initially kinda confusing, but actually very simple in concept, so the starting point would be learning what action hooks and filter hooks are. You don't *need* to know PHP though; that is after all WordPress' whole selling point, but it really helps if you want to keep plugins to a minimum (you really do lol).
Other than that, the best advice I can give you is to save yourself a ton of heartache, and never Google the words "best wordpress themes." WordPress themes are dead imho, and mostly a waste of time (the fancier and flashier they look, the worse they are. I promise).
Instead (here's something I never thought I'd do, recommend a wysiwyg page builder lmao) install Elementor and their Hello theme, which is a plain barebones theme designed to work well with Elementor. There are other page builders, and they are all going to drive you absolutely up the wall. WP Bakery, Avada... all designed to test the limits of the human psyche.
Anyway, then install Pro Elements, which enables most of the features of Elementor Pro for free*, most important being the Theme Builder, which will let you build a header and footer and have them apply automatically to every page.
...that is assuming you haven't already set up the frontend to your liking, and managed to avoid the premium theme hellscape.