If you take money online, in any way, you NEED to have an accessible and satisfying ‘customer service’ type page. Google says, “Contact information and customer service information are extremely important for websites that handle money, such as stores, banks, credit card companies, etc. Users need a way to ask questions or get help when a problem occurs. For shopping websites, we’ll ask you to do some special checks. Look for contact information—including the store’s policies on payment, exchanges, and returns. “ Google urges quality raters to be a ‘detective’ in finding this information about you – so it must be important to them.
In Keyword Planner, formerly known as the Keyword Tool, you can get search volume and traffic estimates for keywords you're considering. Unfortunately, when Google transitioned from Keyword Tool to Keyword Planner, they stripped out a lot of the more interesting functionality. But you can make up for it a bit if you take the information you learn from Keyword Planner and use Google Trends to fill in some blanks.
Google is all about ‘user experience’ and ‘visitor satisfaction’ in 2019 so it’s worth remembering that usability studies have shown that a good page title length is about seven or eight words long and fewer than 64 total characters. Longer titles are less scan-able in bookmark lists, and might not display correctly in many browsers (and of course probably will be truncated in SERPs).
Yes, you need to build links to your site to acquire more PageRank, or Google ‘juice’ – or what we now call domain authority or trust. Google is a link-based search engine – it does not quite understand ‘good’ or ‘quality’ content – but it does understand ‘popular’ content. It can also usually identify poor, or THIN CONTENT – and it penalises your site for that – or – at least – it takes away the traffic you once had with an algorithm change. Google doesn’t like calling actions the take a ‘penalty’ – it doesn’t look good. They blame your ranking drops on their engineers getting better at identifying quality content or links, or the inverse – low-quality content and unnatural links. If they do take action your site for paid links – they call this a ‘Manual Action’ and you will get notified about it in Webmaster Tools if you sign up.

Website owners recognized the value of a high ranking and visibility in search engine results,[6] creating an opportunity for both white hat and black hat SEO practitioners. According to industry analyst Danny Sullivan, the phrase "search engine optimization" probably came into use in 1997. Sullivan credits Bruce Clay as one of the first people to popularize the term.[7] On May 2, 2007,[8] Jason Gambert attempted to trademark the term SEO by convincing the Trademark Office in Arizona[9] that SEO is a "process" involving manipulation of keywords and not a "marketing service."

In short, nobody is going to advise you to create a poor UX, on purpose, in light of Google’s algorithms and human quality raters who are showing an obvious interest in this stuff. Google is rating mobile sites on what it classes is frustrating UX – although on certain levels what Google classes as ‘UX’ might be quite far apart from what a UX professional is familiar with in the same ways as Google’s mobile rating tools differ from, for instance,  W3c Mobile testing tools.

The higher the search volume for a given keyword or keyword phrase, the more work is typically required to achieve higher rankings. This is often referred to as keyword difficulty and occasionally incorporates SERP features; for example, if many SERP features (like featured snippets, knowledge graph, carousels, etc) are clogging up a keyword’s result page, difficulty will increase. Big brands often take up the top 10 results for high-volume keywords, so if you’re just starting out on the web and going after the same keywords, the uphill battle for ranking can take years of effort.

Baseline ranking assessment. You need to understand where you are now in order to accurately assess your future rankings. Keep a simple Excel sheet to start the process. Check weekly to begin. As you get more comfortable, check every 30 to 45 days. You should see improvements in website traffic, a key indicator of progress for your keywords. Some optimizers will say that rankings are dead. Yes, traffic and conversions are more important, but we use rankings as an indicator.