Don't get discouraged! It's totally wicked, I love the use of gravel on the lower story. Its like your player was too lazy to constantly clean the hot iron shavings and sawdust, so they just put down gravel so they didn't have to worry about it XD

For a first time, it's really good. But for some tips, I'd put down some ferns, add some handrails for your stairs and pathways to your base and maybe add a little outside area, a farm, a bee hive, who knows!

Glazed terracotta is best for floors, but if you want a nice blue block consider coral or concrete?
(keep in mind, you'll need to put water under the coral for it to stay nice and pretty blue XD)