Force Click, as the name implies, requires you to put a little "force" behind your click.
By default, Force Click requires a "medium" level of intensity to activate. Apple gives you the option, however, of switching to "light", which makes it easier to engage, or "firm", which requires you to put even more muscle behind it. Whether you're having a hard time triggering Force Click, or you're triggering by mistake, there's likely a setting that's perfect for you.
Note: Force Click is currently available on the 2015 MacBook and 2015 MacBooks Pro, and the new Magic Trackpad 2.
How change the firmness of Force Click on the Mac
- Launch System Preferences.
- Click on Trackpad.
- Select between Light, Medium, and Firm.
Keep trying the different settings until you find the one that works best for you.