It's time you free up your parking spot with the easy ideas you can get done all by yourself. Make sure you set aside enough time to get this done. We'd suggest that you spend at least one full day getting this done.
To start, make sure you go through everything, including all the unopened boxes you have. You never know what's hiding inside. Figure out what's working and what isn't. Take a step back and examine your shelves, the different spaces that you have for storage, and think broadly about places that you can place your items in.
Declutter your garage
Once you've taken everything out of your garage, it's time to get rid of things that you don't need. This might take a lot of time because of sentimental value, but this step is crucial. Make sure you have a ton of garbage bags on hand because you will get rid of a lot of things that you don't need.
Group the items that you want to keep. This will make it a lot easier to put things away once you're ready, and you're able to check if you have any duplicates that you need to get rid of.
Start with the garage storage you have
If you already have shelves, hooks, and storage boxes, make sure you plan on using those first when possible. Only once you've exhausted all the storage solutions you do have, then you can visit a crazy plastics store near you for additional storage.
Make sure it all fits before dumping all your items in the storage spaces you've created. Make sure everything works together.
Start placing your items. Make sure you keep like items together and make sure that things that you use frequently are easy to use. Place heavier items at the bottom and light items at the top.