Welcome. We are here to help!
We all started from nothing and had little to no knowledge. The main thing is to not be afraid to dive in but to also recognize your limitations, before you get into trouble. Most things are just taking them apart and reversing the order for installation. Easy enough just remember how it came apart.
Grinder is spot on about the tools. Most things don't require a vast array of tools or expensive ones, at that.
Those mechanics toolsets, the ones in plastic cases, like sears sell, are a great way to start. You can build on those over the years and as your knowledge and tasks become broader.