If I use a sinple EA based on the EMA crosses, should I set the slippage around 5 or more?   Also, how can define my exits according to another and more reliable thing other than a fixed TP?

What slippage to use for news trading EA?

I really enjoy their training programs

ExNess

Could you please let me know the core strategy of receiving buy or sell signals? On what basis do you decide to buy or sell?

More simple is impossible