You have to perform a content migration, there isn't a method to save as template and import it to SPO (and SPO drops the idea of using classic style 'templates'). Microsoft provides Migration Manager, SharePoint Migration Tool, but there are third parties you may want to investigate such as Sharegate.
You will also need to replace your workflow with Power Automate as SharePoint 2010 workflows are being retired, and SharePoint 2013 workflows will be retired but no current date is set.
In other words, you should be looking at re-architecturing the solution you have to fit within SPO/Teams -- i.e. you may want to move your BI process to Power BI, use Power Automate for workflows (or possibly webhooks + custom code, Azure Runbooks, etc.).
SQL errors are not likely related and may be something worth investigating closely.