This is the forex software simulator I am using; https://soft4fx.com/software/forex-simulator.php
If you want to calculate position size (how many lots for your risk amount) within the simulation software you are going to need this link:
If you are using a live account, you can use this indicator and you can check if the indicator is correct by manually doing it with the baby pips position calculator.
Here is the No Nonsense Position Size Indicator for MT4, double check manually to make sure it is correct.
This is good stuff to know as a basic understand instead of just jumping right into the NNFX Trade EA Assistant or an even better one for your live account. You can double check to make sure the Trade Assistant is also calculating things correctly, too.