No, you don't have to know Spanish in El Salvador. You can get by in most places speaking English. El Salvador is not the same as Mexico, where every touristy location has English speakers. However, you will be able to speak English in most places. Most restaurants have menus in English, and most hotels have information in English as well as a representative to help translate. I would suggest that you download Google Translate on your phone before arriving.

Yes, it is safe but driving in El Salvador is a little different than the US. For starters, there are a lot less big parking lots than in the US so you need to know how to parallel park. All traffic laws are basically the same, but it is illegal to drink and then drive. That means even if you just have one beer, you cannot drive after.

Yes! Uber is a safe and an easy option to get around. Most hotels can also help you book transportation.

:)