QUOTE: The manual actions team… can look at the labels on the on the links or a site gets. Basically, we have tons of link labels; for example, it’s a footer link, basically, that has a lot lower value than an in-content link. Then another label would be a Penguin real-time label. If they see that most of the links are Penguin real-time labelled, then they might actually take a deeper look and see what the content owner is trying to do.” Gary Illyes, Google 2016
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.
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.
QUOTE: “We expect Ads and SC to be visible. However, some Ads, SC, or interstitial pages (i.e., pages displayed before or after the content you are expecting) make it difficult to use the MC. Pages with Ads, SC, or other features that distract from or interrupt the use of the MC should be given a Low rating.” Google Search Quality Evaluator Guidelines 2019
Ask for a technical and search audit for your site to learn what they think needs to be done, why, and what the expected outcome should be. You'll probably have to pay for this. You will probably have to give them read-only access to your site on Search Console. (At this stage, don't grant them write access.) Your prospective SEO should be able to give you realistic estimates of improvement, and an estimate of the work involved. If they guarantee you that their changes will give you first place in search results, find someone else.