Glencore/Vitol Commercial Graduate Programs - Advice for recent grad

I recently graduated from an Ivy a couple of months ago. My current albeit limited experience was really geared towards landing an IB position and I ultimately ended up securing a buyside SA offer in a distressed role for a well-known shop to be in contention for a FT spot meant to lead a PM spot later on. Though I received all positive feedback and was told I was on track to return during my midsummer review and during the internship, they ended up only taking 1 intern. After this, I decided to redirect my focus to law school for an eventual law RX practice group (adjacent to my finance interests) given that I have the requisite LSAT/GPA stats for a T10 school.

I planned and am currently spending the year before I formally apply to LS to helping my dad out with his small blue collar shop (building out a website, contacting and negotiating with clients, dealing with contractors, sourcing low cost materials, etc.) so he can develop and attractive business to sell and retire on. During one of the conversations, I had with a client, a petroleum engineer, he mentioned something about commodities trading, specifically something about Glencore (physical trading). I looked more into it on here and online and am very interested in it. I plan to apply to the Glencore and Vitol Commercial Graduate Programs for the Houston office (given that I am based there now). I understand I would start in sort of a BO/MO in risk/ops and would need to work my way up to trading and prove myself. I was wondering what materials I would need to begin studying to secure these roles and ensure I am the most prepared. From reading around, I see people mention Oil 101, King of Oil, and The International Copper Industry for oil/metals but I imagine the focus in Houston would be oil trading. Any further information on what to study, how to ensure I could get these roles, and general advice on how to best position myself to get into a physical trading house would be greatly appreciated! I also wonder if the cold-emailing/networking approach used by students for IB is industry standard to break in to these firms. I am a complete novice at this but hungry and open to realistic advice.