Can you help me quickly fix my website with a foolproof list of free SEO tactics and actionable tips & tricks?

Here is a simple yet complete list of free SEO optimization techniques and actionable approaches to help you with that (otherwise, the process of getting your site/blog adapted to Google’s organic search listings – as generally opposed to using paid search promotion, a.k.a. Pay-Per-Click ads). Understanding the importance of making your web pages pop up right in front of the target audience in Google’s SERPs, use the following foolproof checklist of free SEO to get started with the right points of the main optimization focus – both at the on-page, and off-page level of organic Search Engine Optimization. That being said, consider emphasizing the following SEO elements to take the necessary action without wasting too much time and effort.

Basic Checklist of Free SEO Optimization for Google’s Organic Search

On-Page Level

• Keywords – before anything else, you should complete in-depth keyword research to set up the right set of the main target search terms you’re actually optimizing for. Take a moment to delve deep into long-tail search terms (i.e., extended variations of your core keywords, which are frequently used by your potential clients/buyers to find what they need).
• Title Tags – make sure to maintain consistent and fully correct formatting for these arguably the most important elements of on-page SEO. Remember to keep up with a 55-60 character limit, in line with including your top relevant keywords closer to the title’s beginning – and you’re done.
• Meta Descriptions – considering that your meta descriptions will be used by Google search engine to display a clickable “rich snippet” in the list of its relevant SERPs, you must pay the most precise attention when choosing the right long-tail expressions to create only unique descriptions for each web page you have with your site/blog. That way, remember to maintain a general requirement to their length – somewhere around 150-160 characters – to prevent them from being displayed incorrectly or, say, in a half-cut mode that will hardly attract many user clicks.
• XML Sitemap/Custom 404 Page – don’t forget to generate a correct sitemap (for example, using online tool to quickly complete the task in a half-automated manner), in line with working well on creating a custom 404 page, which is needed to minimize potential user’s disappointment upon triggering a broken link or non-existing web page).

Off-Page Level

• Social Bookmarking – it may sound like a no-brainer, but dropping external links throughout some popular social bookmarking platforms can be really helpful in boosting your web traffic, and therefore improve your overall organic ranking potential. Consider focusing on platforms like Reddit, Flipboard, Pearltrees, StumbleUpon, etc.
• Business Profile – creating personal business profiles on some popular social media platforms (like Facebook, LinkedIn, etc.) can help you not only attract more natural links with your articles/posts, but help you build better public awareness and stronger brand name among your precisely-targeted potential clients/buyers.

• Local Listings – make sure to get your website submitted to local directories/business listings. That will contribute to your overall SEO effort, in line with giving you extra link building opportunities within a given focused region or city/town.
• Guest Blogging – can also become a nice way to maximizing your website’s SEO performance at the off-page level. All you need is to produce a high-quality and 100% original article/post to be published on a previously settled third-party source relevant to your product/service or main topic – and you will get a valuable backlink in return.