You can sell your bitcoin to get ETH and XMR now but if you wanted to sell bitcoins for eth and XMR, wait for this two coins to dump and have cheaper btc buy and sell rate. Don't buy when both of these coins when they gained value. You can monitor for the right time by using as that monitor price movements of crypto like coinmarketcap or blockfolio. Choose the one that is more comfy for you to use.