you can make a thread on blackhatworld marketplace

always do a monthly site audit, use screaming frog to check your website if there is a broken links on, missing h1 and meta tags.

Create valuable content once or twice a week to recover, google would love that as he sees some updates on your website.

+1 from @binayjha that is the best way to get free do follow backlinks. Ahrefs can help you to get your competitor backlinks, if you are really tight on budget you can go for some seo group buy to get an access to ahrefs in a cheaper price.

Follow the backlinks of competitor websites and try to win backlinks from those for your website.

try to subscribe to Aleyda Solis for latest search updates and SEO news. There is a lot of personalities which is covering SEO news and updates

Create a backlinks with high DA/PA. Create more valuable content it will take long but it will effect on the long run.

create also a blog which gives a positive feed back to your company with a longer and optimized content than the bad blog content.