Press your lips together to stop the air, then release. No vocal cord vibration.

Americans pronounce perch as PURCH (/pɜrtʃ/). You'll hear it in sentences like "Search the earth for the perfect perch".
Record yourself saying "perch" and play it back. The mic stays on your device — nothing's uploaded.
1 syllable, 3 sounds. Explore each sound's mouth shape and how it's made.
Press your lips together to stop the air, then release. No vocal cord vibration.

Flare your lips and push them away from the face. Lift the middle of your tongue toward the roof of the mouth.

Touch the front of your tongue to the roof of your mouth, then release into a 'sh' position. Flare your lips.

The textbook way isn't wrong — it's just not how anyone actually says it.
Americans use a relaxed retroflex R — the tongue curls back rather than rolling. The R is one continuous sound with the vowel before it, not two separate sounds.