If you create a sales page for an informational keyword, Google won\'t rank you because you aren\'t giving the user what they want. Matching intent is the most important factor in modern SEO.
Search the keyword yourself and look at the top 3 results. If they are all "How-to" guides, the intent is Informational. If they are all shop pages, the intent is Transactional.
Yes, these are called "Mixed Intent" keywords. For example, "Camera" could be someone wanting to buy one, or someone wanting to know how they work. In these cases, content that covers multiple angles often performs best.