Newbie here and I want to start trading soon. Just want to get tips on when to invest on btc and eth. thanks in advance! 
You can invest whenever you want. You just have to look at the charts on the market and if you see the price is going down, that's the right time to buy it and start investing. But for now you better invest in ETH if you want to start now. And if you believe bitcoin price will reach $3k then now is the right time to invest in bitcoin.