Phone [Q] Kindle Fire HD7 11.3.1 Rooted. Now what?

I am a complete and total noob for all things Android. I didn't even know what "rooting" was until last week when I got a Fire HD7 and hated the UI and started Googling how to change it.

I found this forum through said Google search and successfully rooted my Kindle Fire HD7 (11.3.1) and a BIG thank you to those who put in the work to make it SO easy. Now I'm ready to modify but have NO idea what's next. I tried searching the forum for posts about what to do but didn't come up with anything that would fit the HD7. So can anyone steer me in the right direction? I can (and do) read and follow directions quite well so even past posts if there are any would be a huge help. What do I need to do to change the UI, modify things like screen savers/back grounds, put Jelly Bean or something on it, etc...

Thanks in advance for your guidance.