Software development workflow and productivity

Hello! I hope all is well with you. I'm seeking your advice and recommendations. Recently, my boss informed me that I'll be leading a team of three people next year. I'm interested in your insights on boosting productivity and fostering collaboration within the team. Specifically, I'm looking for workflow recommendations to streamline development.

I want to be transparent about my background—I've been a web developer for five years, but I acknowledge that I'm not well-versed in programming workflows. I currently don't use GitHub, and our testing is done manually without a testing framework. Our ticketing system is an Excel file containing bug details and status. Despite my experience, I'm eager to learn and enhance my skills. We primarily work with CodeIgniter 4 and jQuery, developing in-house web apps for our food manufacturing company.

If you could suggest any helpful links or setups that you currently use, I would greatly appreciate it. I'm committed to improving my skills and our software development processes. While it might be a bit late, I'm determined to initiate positive changes and potentially influence other teams in the future. Thank you for your assistance.