Google will select the best title it wants for your search snippet – and it will take that information from multiple sources, NOT just your page title element. A small title is often appended with more information about the domain. Sometimes, if Google is confident in the BRAND name, it will replace it with that (often adding it to the beginning of your title with a colon, or sometimes appending the end of your snippet title with the actual domain address the page belongs to).
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.
SEO is the practice of optimizing websites to make them reach a high position in Google’s – or another search engine’s – search results. At Yoast, we believe that holistic SEO is the best way to rank your website because you focus on making every aspect of your site awesome. Don’t use any black-hat SEO tricks, because eventually, this will have negative consequences for your rankings. Instead, practice sustainable SEO, with your user in mind, and you will benefit in the long run.
There are a lot of definitions of SEO (spelled Search engine optimisation in the UK, Australia and New Zealand, or search engine optimization in the United States and Canada) but organic SEO in 2019 is still mostly about getting free traffic from Google, the most popular search engine in the world (and almost the only game in town in the UK in 2019):
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.