Could you help me to learn the piano?

i learn pretty quickly, i've been playing it (the keyboard really) for two and a half weeks and the song i've been trying to learn is rage over a lost penny and i can play like twenty seconds into it, where there's a series of sixteenth notes that lasts eight measures that go down then up the staff, (i can go down but find going up it more difficult) and i'm self taught so in order to become good enough to play this part, i need some sort of lessons or something. i asked a question on how to execute that specific part and got no helpful replies, so maybe the question i should ask is are there exercises i can do that will make me capable of doing things like that? or maybe set me up with some sort of disciplined schedule (for example play _____ song at half speed by the end of the week and full speed by the end of next week etc.) i will never give up on learning this, i've always wanted to learn and now i am so if you still think i'll give up because i'm rushing or something then recommend a lighter schedule please. i'm broke and have nobody to teach me so any guidance would be greatly appreciated. thank you for reading this!