How do I get Recipes

AFAIK, you can't do this with blocks, or with code for that matter, don't quote me. There are, however, two ways of getting recipes easily:

1. Typing in the command /recipe give @a *
What this command does is self-explanatory - It will give you every recipe for every item, including modded items. You can change the * for minecraft:* or <modname>:* to get recipes.

2. Using a mod that shows recipes, like JEI (Just Enough Items)
Just Enough Items, along with any other inventory-type mod that has this feature, allows you to see the recipes for certain items.

You cant edit Vanilla recipes they are hardcoded by MCreator

All internal Minecraft recipes are located in their respective .JAR files in the .minecraft/versions folder. So if you wanted to get the recipes for a version of Minecraft, lets say 1.12, you need to have downloaded the 1.12 version from the launcher, then go to .minecraft/versions/1.12/1.12.jar and open via WinRAR/7Zip. The recipes are in JSON format and can be found in assets/minecraft/recipes.

You cannot access the crafting recipes that are built in Minecraft, i.e. Bows and Swords, in custom crafting blocks using MCreator, as MCreator does not use the same crafting mechanics as Minecraft's internal MATTIS system. You have to make recipes through the "Recipe" elements, which do work with the vanilla MATTIS Crafting Table, or through Procedures/coding, which only work with custom Crafting Blocks with inventory.