Ok. You're discussing "plug-ins" and "add-ons" when you're actually asking about Effects (FX) like NewBlue, color presets and LUTs along with other settings like exposure and contrast in the Fix/Enhance tool.
CL refers to plug-ins as individual separate modules like the Multi-Cam Designer and Action Camera Center (they're listed under the Plug-ins menu) but none of them are useful for the kinds of changes you're looking to make.
To my eyes, you footage looks like genuine 8mm content and I'm not sure what you're looking to change.
You could bring out bolder colors by using a Color Preset like Underwater or one of the Landscape HDR Warm/Cold color look-up tables (LUTs). It will take a long time to render the final video so make sure you like what you see before producing.
You can split your timeline clips if necessary to apply different presets or CLUTs to different scenes, and you can add an FX track below the clips and place NewBlueFX or BorisFX there.
I hope some of the other members with more experience will chime in now that we can see what you're working with.