How to test my system Performance?

The first thing you need to look at is the market context. 4 types of context such as volatile / non volatile / impulsive / and corrective. Trading is done by combining support and resistance levels with these 4 things but the amount of loss will be reduced a lot.

If you want to become a good and professional trader you need to have a plan to deal with the losses. If you can deal with the losses it is possible to overcome the loss and make a profit from this market.

You need to backtest your strategy to know its worth. I personally find moving averages very simple to grasp, and something that has been working profitably for me for the last couple of months.

To achieve a result, you need to spend maximum time and effort, and then you will receive a certain income.

Plan out your strategy and use it on the demo account for the time being, so that you get an idea about how it will be later. You can keep testing different strategies and then analyses them accordingly.

You just need to learn to control your emotions, not to panic, focus on this, develop a strategy correctly, test it on a demo account, and then the risks can be minimized.

Backtest it or try in the demo account.

You can test your strategy or your system only either on demo or real accounts. Of course, you can apply to expert advisors however I don't think it's a good idea because you will have to pay for them.
Anyway, try to stay on demo for couple of days and test your strategy. It's the most reliable option for you and you don't even need to risk your money, because on demo they're provided by the broker.
So, after your successful testing you can move on to the real account and test your strategy on a real one, when you will see that your strategy don't work anymore, change it.