I was given 250,000 dollars to invest for 10 weeks. No brokers fees and no overhead. I had a balance of 3.04 after investing the rest. I made 301,124.000 dollars after selling my investment. How do I present this in a trail balance for my teacher?

So your “company” had 250,000 in cash.

You then invested $204, 996.96 (so let's just say you invested $250,000).

That JE would have been:
Dr. Investments 250,000
Cr. Cash 250,000

Now you have sold the investments for let's say $300,000.

So that JE is:
Dr. Cash 300,000
Cr. Investments 250,000
Cr. Gain on Investments 50,000 (a revenue account, goes on the Income Statement)