Lets do a small breakdown on the possibility of earning 15 - 20 euro a trade.
You have a 4k balance. That would be a 0.5% average daily increase of your account.
I’m going to assume you will follow proper risk management and risk 1% of your account per trade. That gives you a 40 euro risk per trade.
If you take a reward to risk ratio of 2/1, for every 40 euro that you risk, you stand to win 80.
I’m going to assume that you have a strategy. Lets say in a week, you take 10 trades, and you win 4 and lose 6 for a win rate of 40% (in real trading strategy, we will need a larger span of trades to get the correct win rate).
Wins: 4 x 80 = 320 euro
Losses: 6 x 40= 240 euro
Net = 80 Euro
That would give you an average profit of 16 euro a day over the week of trading.
With your account balance, yes it is possible to earn your target over a period of time. Is it recommended to start on this? If you are a beginner, then its better to start on demo and refine a strategy that you can test first before diving head first. A lot plays into trade, especially trading psychology.
Being able to use correct risk management will also help improve your chances of success, but it is not so easy to stay disciplined sometimes, after all, we are humans, we make mistakes.
With that being said, I wish you luck with your journey.