Good advice all, I have followed wp's approach.
I have been actively using Lazarus for over 9 years and am still learning. I currently maintain 3 large scientific projects that share a library with graphics, math, and general routines. For many years I simply added the paths of all the library directories to the project path.
This is very simple, and you can start there, but it started to get unwieldy with multiple projects on three platforms, so I started experimenting with packages. This is more effective, but I still get confused occasionally.
I have only in the last few years begun to use git, which is great but has a learning curve. I am moving towards open source so it is critical. Prior to that I simply zipped a project before making changes, applying a standard versioning number.
So, in my case, I have been incrementally improving my organizational skills, rather than jumping in with both feet.