You actually are able to make terracotta blocks. All you have to do is smelt a clay block to give you terracotta. You can also dye the basic terracotta by surrounding the dye of your choice with 8 terracotta blocks. Hope this helps!
After some of your current building projects, I've always been a big fan of building roller coasters. I always love making a huge drop offs that fall on more tracks. But I think it would be cool if you started making one of your own coasters. You're great at building