I wouldn't recommend the tileset you're currently using, as it's really really old and doesn't use ZC's newest features.. I highly recommend you switch to the Vintage Dreams tileset here: https://www.purezc.n...=tilesets&id=96;as it comes packed with all sorts of GB-Zelda enhancements and the like set up and ready to go.
For entrances, change the "Combo Type" of the entrance combo from "Cave" to "Stairs". This makes warps instant. To decide where it leads to, click Screen at the top of the editor, and click "Tile Warps". Screens can have up to 4 different "Tile Warps" (AKA 4 different destinations when stepping on a warp combo). For example, Stairs (A) corresponds to Tile Warp A, Stairs (B) corresponds to Tile Warp B, etc.
You also need to set up DMaps. These can be created via Quest at the top, and then DMaps. These hold the data for locations, such as the map title, the map graphic, what screen you respawn on when you die (probably not important if doing a GB style game), what palette is used (this is important! You want to set a good palette to give your areas unique colors. If you don't everyone will hate your game for being boring. You also need to set these as dungeons usually have their own colors.), what music is used, and the like. Be sure to look through and set all the things that you need to!
For building areas, it is highly recommended to use CSets 2, 3, and 4 only. These ones correspond to what palette you are using, and most often have the most fitting colors. Every other CSet is a "Sprite CSet"; people will criticize you if you use these for building. To change what CSet you are placing combos down on, press the "+/=" and "_/-" keys; the former increases your CSet, the latter decreases your CSet.
Hope this helps!
Edited by Dimentio, 31 May 2018 - 08:40 PM.