What Ad Channels you use will be dependent on your business, product, cost, strategy etc. Advertising an impulse buy for cosmetics is probably best suited to Instagram as opposed to LinkedIn, while a new SaaS company would likely be better suited to LinkedIn ads then cold traffic from Google or Facebook.
Also the targeting options of these platforms will vary greatly depending on how they track users, what information you have access to, and how their algorithms best decide who might be interested in your product or service.
At the end of the day there are a few main things to keep in mind which will help propel your forward regardless of the platform.
We will look at each of these in more depth later on in the course, but start to think about how you want your messaging, branding to come through on your ads and who your ideal target audience (or persona) would be.