Forget the imperial measurements, especially if you grew up in the United States (which uses pounds and feet instead of grams and meters). People who grew up with the imperial system may struggle when they try to convert everything with complex equations. Learning the metric scale should take place on the elementary level, the way all other people around the world learn it. The imperial system just gets in the way.
Remember that numbers are often smaller in the metric system. For instance, in temperature, Celsius uses much smaller numbers than the Fahrenheit system. 30 degrees Celsius is considered warm where 90 degrees Fahrenheit is warm in the imperial system. Having to know smaller numbers is much simpler than the imperial system where you will use higher numbers for varying degrees. Forget these large numbers and focus on the mentality that not everything needs to be in the extreme.
Begin to measure things in the metric scale as you begin to learn. This will give you additional practice in the art of the metric system. If you need to, write everything in the imperial system as well as the metric system. You do not need to convert everything, just know that the metric system will be evaluated in smaller numbers. If you have to, memorize the metric equivalents to imperial units; this will help with your practice.