This is a standard that was probably more popular in the 1960s and 1970s than it is today. It was actually written in the 1950s, but has a fresh, happy sound that is more typical of the following decades.
This song is deceptively simple. The melody is interesting and memorable owing to some large interval jumps that remain within the diatonic framework (think "Somewhere Over the Rainbow"). And the song is a very conventional AABA form.
But don't get too comfortable in the A section because the B section (bridge) is in a completely different key center, presenting the same kind of challenge you get with tunes like "Have You Met Miss Jones?"
The A sections have very familiar changes in the key of F concert. This uses the so-called "backdoor progression." The usual ii-V progression in F would be Gm7-C7-F. The backdoor progression is iV7-bVII7 or Bbm7-Eb7-F. Many songs use this pattern, and it is well worth practicing this, just as you would practice a ii-V. Here is a site that goes into more depth and lists a bunch of tunes where you will find this important little trick. In addition to those jazz standards, there are many pop tunes that use the back door: e.g. Stevie Wonder "It Knocks Me Off my Feet" which goes straight to the back door in measure 3 and Billy Preston's "You Are So Beautiful" which is almost nothing BUT the backdoor progression.
So, practice the backdoor pattern to master the A section. Then get ready to go with the flow in the bridge. The first 4 measures are in the key of D major. The next 4 measures are in C major, ending with a C7 to send us back to the key of F for the final A section. Practice your scales in F, D and C to get warned up for this tune (and throw in some Eb practice to handle that backdoor business.)