Contact the company directly. If you use a product or service and want to recommend it but you can’t find evidence of an affiliate program, consider approaching them and asking if they are willing to set one up (maybe with your help). Highlight your audience and the value of your recommendation. Explain that an affiliate program is simply rewarding happy customers (you!) for promoting, and they don’t have to pay until a sale is made.
The topic you choose must have enough depth that you can create a lot of content for it. This is important for building an authoritative site, for search engine optimization, and most importantly, for the end user. If you don't have enough content about a topic, you're not going to be taken very seriously as an authority on the topic and it's unlikely you can convince someone to make a purchase from you.
If your domain is your address, hosting is like the actual house within which your site will live. It's your own little slice of the internet — the place where all your website files live. Hosting is very affordable these days, so don't unnecessarily scrimp on costs. Go with a reputable, reliable provider because your affiliate marketing business depends on it.
Some merchants run their own (in-house) affiliate programs using dedicated software, while others use third-party intermediaries to track traffic or sales that are referred from affiliates. There are two different types of affiliate management methods used by merchants: standalone software or hosted services, typically called affiliate networks. Payouts to affiliates or publishers can be made by the networks on behalf of the merchant, by the network, consolidated across all merchants where the publisher has a relationship with and earned commissions or directly by the merchant itself.
Now as to your comment on traffic it is true, traffic is important. But the truth is, acquiring traffic is easier than converting it. Plus we have many posts dedicated to traffic generation on this blog. Simply check this post, this post or this post. But must importantly, the reason why people struggle with traffic is that they try to promote a sales page or a heavily biased piece of content. Nobody wants to share that, nobody wants to link to that, and as a result you don't get traffic and blame your lack of success on traffic (like you did in your comment above).
Making Sense of Affiliate Marketing is a great learning tool, even if you are a brand new blogger. By taking this course, you will start off blogging the correct way. You can learn from my affiliate marketing mistakes and learn the best ways to start making an income by being an affiliate. Through taking this course you are sure to grow a profitable blog quicker than the average blogger, as you'll learn exactly what you need to know about affiliate marketing. So, even if you only have one blog post, you are ready to get started with this course!