Actually there isn't much changed in the way furnaces behave in 1.12 and 1.13. The main difference being that recipes can now be customized using config files, but there aren't many gameplay changes on this front. Even in 1.12 you will get XP when smelting certain items (such as ores). Basically you get XP from smelting blocks when they didn't give XP while mining. Coal, lapis and diamonds immediately get you XP after you mined them (not with a silk touch pick of course) but the metals like iron and gold do not. So that's basically "postponed" until you smelt them and get the actual items. But that wasn't changed in 1.13. This wiki page might be of some help to learn about the differences between 1.12 and 1.13.
I'm definitely looking forward to it. I can have the river gates of my castle properly waterlogged to look more natural, and I'll begin buying Nautilus Shells en masse from people wanting to sell them to me I'll also fill my river with Kelp so that I have a reliable-ish, manual kelp farm ...My only hope is that I'll eventually get some Salmon in my river, too. The more food sources the better, right? AND I'm planning to add a couple of Cod to my fishing dock for fun, but we'll see how that goes I guess
I wonder how the fish will operate in town, will they be fluid from res to res or will they be stuck to one res
-- Minecraft 1.13 added the most new blocks out of any major Minecraft update ever, with technically over 70 blocks total: 6 Wood (bark on all six sides) 6 Stripped Logs 6 Stripped Wood 3 Slabs and 3 Stairs 15 Coral-Type Blocks 15 Dead Coral-Type Blocks 5 Trapdoors, 5 Buttons and 5 Pressure Plates Kelp Plant and Dried Kelp Block 2 Sea Grasses (1-high and 2-high) 2 Bubble Columns Conduit Blue Ice 1.12 comes in second place at 63, including colored beds, 48 if not including the block entities. 1.14 could have ever more than or about as many new blocks as 1.12 or 1.13. Mojang has finally removed the Block ID limit of 256 block types and all the hexadecimal metadata associated with them, in favor of block states or separate IDs. This monumental accomplishment makes me excited for 1.14 and beyond more than 1.13's building additions. There will be many new slabs and stairs and other blocks coming in 1.14 alone, yet it will not be a building-themed update.
I’m way stoked for the coral reef stuff!! I am thinking about building a small area like maybe a turtle sanctuary. But that’s after my big project finishes up. I am also thinking of setting up turtle adoptions lol. I adore sea turtles in real life and donate monthly for their care through the WWF. You should look into it if you’re more curious!!!!! I am also excited to see how the community delves in the new update too!