Create teleporter for story game

hi , I am trying to create teleporter for game using this link - Intro to Game Design - Core Academy
I am stuck in ' Customize the Teleporter' . i have removed the cylinder and pipe and selecting deinstance it. Then i selected trigger in geo and cant resize it as per my needs. In an open terrain , player can fall anywhere . So , i think i want it to be really big but this resize doesnt work .
In the 'add a target' drag your spawn point in custom section cant be selected .
I have no coding experience just in case i am facing these issues because of that .

Sorry if this is missing from the instructions:

The teleporter is a template, so it tries to keep you from changing it until you deinstance it.

Right click the Teleporter in the Hierarchy and select "Deinstance This Object".

Does that solve it?

I haven't really messed with resizing the Trigger, but if you look in the Properties for Trigger, in the Gameplay section, you can change its shape. Maybe try changing it to Box instead of Capsule then stretch that out. The capsule shape probably won't work well for what I think you are describing.

For your target, you can just make a cube and flatten it out on the ground. Make sure to uncheck collision so you don't get stuck in the cube when you teleport.

In order to get the target to work, you need to select that item in the Hierarchy and drag it into the blank for "Target" which is found in the Custom section of the properties window when you select "Teleporter" in the Hierarchy.

Thanks. The solution i found out from your solution was that simply insert a cube in your game . In target of Teleporter , drag cube from heirarchy . Resize cube as you like. Move your cube wherever you like.

When i said

i was trying to select things from core editor . It has to be dragged from heirarchy .
That was how i was facing problem.