You of course, want the trade details. Ticker symbol, number of shares, date purchased, date sold, amount paid for shares, amount realized from the sale, gain, loss, percentage gain or percentage (loss). Of course, from all your trades, you use your formulas to measure your average gain vs average loss, win and loss ratio, win percentage, loss percentage. Now, you use this data to figure out your trading edge or expectation of whether your trading system has an edge. Your trading system has to have an edge or positive expectation. Then, you know you will make monies over hundreds or even thousands of trades. Do not forget to backtest your trading system to make sure, it actually works in market conditions. You want to review trades you have closed and add notations at the bottom of the trade record for mistakes you made, or good things you did. After a while, your trading records will reveal mistakes being made, over and over again. Not a good thing. Fix that. That way, you can improve your trading performance. I am a self-taught trader so, learned all of these things by myself. I did not have a trading guru teach me.
I record every trade with the info I need at tax time. I can use that data to come up with statistics I or others might find interesting. I journal whether I followed my plan and if not why not. I'm trying to take the emotions out of the process. Not much to journal now as I'm pretty good at following my plan.