I've given up scraping btw. I just put on a lighter coat of wax and let it come off naturally. I'm not racing, so if I want to go faster I turn less
OP, the only way you'll screw it up is if you let the iron get too hot and/or let it sit in one place too long. Use a cheap iron from goodwill or the Sally Anne or whever you can get a $5 used iron. As long as it has a temp control it'll work.
MAKE SURE YOU SCRAPE WELL. Leaving a layer of unscraped wax on your board is worse than not waxing it at all. I use a texture bad and a stiff nylon bristle brush to texture after scraping, but everyone seems to have their own rituals after scraping.
Don't over think it, it's fun...