Replacing thick wheels with thinner ones
Your problem is that you're riding a BMX bike.  While you can certainly go narrower than 1.75, you can't go much narrower -- maybe to 1.5" (3.8 cm) with the same ISO 406 wheels.  You might be able to switch to a slightly larger ISO 451 rim and get down to 1-1/8" (2.8cm) width, but it would be quite expensive to swap the rims and spokes, and the tires might not fit your frame anyway.

If rolling friction is an issue for you you'd be advised to switch to an "adult" bike.  Just about any "adult" bike, new or used, will roll significantly easier than the BMX bike -- they're designed for hot-dogging, not riding any distance.