What should I know for welding.. ?

What should I know for welding?.. so I am in Job corps for welding, and I've heard that there's certain math I need to know, and honestly I'm not the best at math even when I finished high school, I wasn't the best at math. So could anyone let me know what type of math I need to know. Another thing Is that I had a question about is how is welding for you guys, like could I get some pros & cons for welding. And things I need to know for welding, also could I some inspiration for welding. Thank you!