There are lots of ways to structure such a deal. An important consideration is whether the startup exists as a distinct entity yet or is it just on a napkin somewhere.
For a real business that is already structured, it depends on whether they've issued stock or are offering membership in an LLC, etc. If it's just a notion of a business, you can do a letter of understanding or general agreement dividing equity in an entity to be formed later.
If you are going to structure the deal based on a template that you got from an internet forum, you are sowing the seeds of failure around the deal. Before doing an equity deal, I would learn the language of such deals OR find a good attorney.