Well, you could always just buy cheap hydrocarbon wax, it's like 10$ ish for 90grams, a brick sized bar.
Heat iron, place bar on base of iron, coat the entire length of the ski. If you don't use enough wax you're going to burn your base.
Ideally, you want to let it cool for a minimum of 20 minutes. Then hold your scraper with thumbs facing, and scrape tip to tail.
Scrape til nothing is coming out of the base, then follow up with a brass brush, tip to tail til nothing comes out. I then follow with a horse hair and a nylon, but I race...
You should be fine with just a brass brush. If you don't scrape dirt and crap in the snow will rape your base.
Brushing is key.