ETH and LTC are both listed on Coinbase. For credit cards, that's probably the easiest choice as long as you don't mind verifying your identity.
Coinbase is not available in many countries. I think changelly will be a good option as it accepts credit card payments. I haven't used it , but heard about it . I will try this exchange in this week because coinbase is not available in my country also. But heard they charges a bit high for purchasing cryptocoins via credit cards.