Banana coin thingies (i forgot what they were called, lol): go to the first ever level of the game and enter the captain's quarters (which is near the beginning of the level). Run to the left end of the room and jump as high as you can. You should get more than one coin, if you didn't, you could always jump again and get the rest.
Lives: go to the first stage of crocodile cauldron. (make sure you beat this level before you try this cheat) at the very beginning of the stage, you should see a small kind of cliff. Use your team jump to go on the top of it and and grab the treasure chest. Throw it at an enemy, and claim your lives. Asap, press start and return to the world "map". Repeat as much as you like.
Remember, this is not an official or stolen cheat. It was 100% invented by me. U're welcome!