Hi Tee. Welcome to the site.
I'm relatively new myself and what I found extremely helpful to learning to play by ear is learning theory- how to build chords from triads to extended chords; chord progressions; the circle of fifths, etc. This site is a good place to learn a lot of it.
I also purchased a book from Jermaine Griggs. I think it's called "How to play piano by ear". It's 300 pages full of theory and exercises geared toward teaching you to play by ear. You can find out more at
www.hearandplay.com. This is how I started about 1 1/2 years ago. I'm not totally there yet, but that's mostly because I don't have a lot of time to practice. I feel like I can play any song by ear, though I'm still learning runs, riffs and things like that.
I hope this helps.