After all your work, it is a good thing to verify that you did a good job by performing an SEO audit for your Joomla site. There are quite a few tools and services for this. Most of them are commercial ones and they are most suited for experienced people. With limited SEO knowledge, it is often hard to interpret the results the tool gives you.
A free (for sites with 100 URLs or less) desktop tool that can crawl and scan your sites is Screaming Frog SEO Spider. This is a very popular SEO tool. Next to that, WebCEO.com and Semrush.com both offer free plans that also include a full on-page SEO verification, plus some off-site features as well, like rank tracking, social media tracking, and Analytics integration.
SEO Minion
For smaller actions, I often use a Chrome extension in my browser. There are quite a few, but a personal favorite is the SEO Minion extension. It is a very nice tool to quickly read the SEO parameters for a page, like the page title, the meta description, word count, canonical URL, etcetera:

Also, the extension can detect and highlight dead links on a page.
SEO Powersuite
Personally, for my projects, I mainly use SEO Powersuite. It is a desktop suite of 4 tools, that all can be used for free with some limitations (you cannot save projects). But contrary to many cloud SEO solutions, you don't have to pay large monthly sums for the paid version. It is basically a one-off fee to buy the product, plus a minimal fee to keep the product up to date.
Of the 4 tools in the suite, I mostly use the Website Auditor. I simply paste in the URL of the site I want to audit and then the tool starts checking all URLs of the site for issues:

It checks for many, many issues, like:
- Broken links
- Broken images
- Missing or duplicate page titles and meta descriptions
- Correct lengths of metadata
- Correct set-up with regards to www / non-www set-up
- Correct use of SSL
- Redirects
- Canonical URL's
- And much more
Also, it generates a full list of URLs with all properties, like page titles, Robots status, use of H1 headings, etcetera. You can easily export this list to a spreadsheet for further analysis, usually revealing even more issues than the actual audit already revealed.
One of the features I like most is that it checks the Google index for Orphan pages: pages indexed in Google that a 'normal' crawl did not discover. This means: URLs that are not accessible through navigating the site as a user. Many sites suffer from this and it reveals pages you might not even remember you had them. Usually, they are worthless and harm your SEO: why have pages that cannot be navigated to? Now that you know they are there you can get rid of them or redirect them.
Other tools in the suite are a Rank Tracking tool to monitor your rankings in Google for the keywords you entered, a tool to check backlinks to your site, and a tool to discover new link opportunities. Especially the Rank Tracker is a tool I use a lot.
So, SEO Powersuite is a tool I highly recommend, and you can try it out for free at Linkassistant.com:
Download SEO Powersuite for free