redirect_wc_pmpro_shop.php

<?php

function my_redirect_non_members_example() {

	// Check if a non-member is trying to access any other page besides the above or home page.
	if ( is_shop() && ! pmpro_hasMembershipLevel() ) {
		wp_redirect( home_url('login') ); //redirect to home page. Change home_url() to home_url( '/page-slug' ) to redirect to specific page.
		exit;
	}
}
add_action( 'template_redirect', 'my_redirect_non_members_example' );