Step 1. Learn coding. Step 2. Download tModLoader. Step 3. Code.
Terraria Community Forums
MinieK
◄♌мαɴdroιd♌►
Miniek where I learn the coding and where are the codes
MinieK
Search up basic c# tutorials on Google, the coding language Terraria is written in. Then when you get a grip, go to the tModLoader official thread and read.