theoi is a great place to start to get a crash course on the different gods and mythological figures and then from there you can move on to the actual sources!
the iliad/odyssey are the most obvious ones. if you want to go chronological, read the iliad first, but the odyssey is probably easier reading for a newbie. be sure to get a good translation like fagles. i know they’re a little overwhelming, but that probably is the best place to start in all honesty!
the homeric hymns are nice too - little bite-sized stories about the gods (again, be sure to get a good translation), and good if you feel a little overwhelmed. you can also try reading the tragedies (again: get a more modern translation) - i wouldn’t read the oresteia until after you read the iliad, but the bacchae and oedipus rex are excellent reading material and pretty digestible for a modern reader.