[Project Management Tools] Improve task tracking and visibility

I am a part of the content marketing team at a digital marketing agency. We are a team of 3 people, with 3-4 more to be hired in both full-time and internship positions. I want a way to keep a track of all our projects and individual/group tasks in a single place, so that they’re no confusion, overlap, or bottlenecks . Here’s how our modus operandi looks: 1. We offer a number of deliverables, including guest posts, blogs, website content, content gap analysis, content briefs, blog audits, and Reddit submissions for our clients. 2. Everyone in the team manages different deliverables. I might be handling the gap analysis and blogs, and my teammate could be handling guest posts and Reddit submissions. 3. The timelines of each project are more or less the same, with a common final deadline for every deliverable each month. 4. We also further outsource a lot of our work to freelancers, and have to proofread that content and keep track of their pending assignments on top of our own. 5. The need for flexibility in our team is high, as priorities change, projects stop and start again at random, and the number of deliverables can increase or decrease every month. I need suggestions about how we can manage our workflow better and keep things organized. I want to avoid a situation where someone from the team is absent, and the others have no clue about what they did or didn’t do. Any free project management tools or spreadsheet templates that you guys can suggest would be great. Any other advice is welcome as well:)