Procedural Generation question!

[atomic lotus]

I want to create an island for my top down gamae, and i need to create it with tilemap terrains, i didn't find any video related to this only procedural generations with just colors like grass is green, water is blue, but i need with my tiles.There is my terrain example.

[honest raven]

Not a 2D guy, but I think what you are looking for (in broad strokes) comes in two parts:

1. Look into Autotile, which will handle edges and such for you (if you haven't already)
2. Learn how to do procedural generation from one of those videos that does it with colors, but replace those with tiles using your tiles (I'm not sure, but I think you use TileMapLayer.set_cell for each grid point)

EDIT: I'm guessing the "terrain" in your screenshots means that autotile is already handled. So it is just a matter of figuring out how to handle using set_cell in place of whatever the tutorials you have watched are doing

[atomic lotus]

yes i am using autotiles and the problem is that i am new to coding and have no clue how to code it without any youtube video thats is why i was using set_cell method

[tribal oxide]

If you're new to coding, i highly suggest completing this interactive tutorial
https://docs.godotengine.org/en/stable/getting_started/introduction/learn_to_code_with_gdscript.html