So I am planning on putting 500 euros on Eth and Btc each(1000 in total) to hold for long term.
Nice choice, good thing that you are not asking any other coins that doesn't have clear future and long term plans for their investors. You're in good shape with bitcoin and ETH so 500 euros for both of them is a good investment.
Is it a bad time to invest in those crypto-currencies?
In bitcoin it's definitely always a good time to invest on it as the price keeps on increasing just don't be upset when the price starts to decline. That needs to happen for a while but after that it will pump again and with ETH it's a good time to invest now, its price decreased.