You can try it and see which one you have feelings for. But I'm afraid you'll soon get bored in this aimless situation, because you may not know what Buddha and mantra are doing. We can't stick to something that we don't understand at all and can't benefit from. My personal experience is that we must first understand the logic of learning Buddhism, then we will know how to practice, then we will know that all Buddhist methods are blind, then we will know that there is no difference between chanting Buddha and chanting, and then we can really talk about practicing a Buddhism.