I have been trying for months but still not able to get my pinky perpendicular or to apply significant pressure with it. I've tried a few basic exercises, repeated hammer ons, etc. Does anyone have any ideas on how to make progress? I'm a beginner who has taken up the instrument fairly late in life. The instrument I'm using is a Fender CF-60.
To get your pinky perpendicular to the fretboard, the geometry of your hand as it relates to the neck must permit the proper orientation of your pinky to the fretboard. For example, if you hold your guitar too low and your forearm is below parallel to the ground, you may not be able to get the heel of your hand below the neck to facilitate the proper attack angle of your pinkie.
Be sure your playing position allows the heel of your hand (particularly on the pinkie side) to rotate to a position below the neck of the guitar to allow you to get your pinkie perpendicular to the fretboard. The higher above your waist you position the neck, the easier this will be.
Also, in most cases it will be easier to get your pinkie perpendicular to the fretboard if you position your thumb closer to the center of the back of the neck as opposed to wrapping your thumb over the top of the neck.
As far as strengthening exercises, your best bet is to play chords that require the use of your pinkie often. The strength will come with time and practice (with emphasis on time).
Proper form is essential. If you are not sure about your playing position, hand position and form, it might be a good idea to have a qualified and experienced guitar teacher evaluate your technique and how you hold your guitar and position your fretting hand. It may be that an adjustment in technique or position may be all you need.
Good luck and have fun improving your playing skills.