Parse error: syntax error, unexpected ‘}’ in

In that last block, there’s a mix of bracketed and bracket-free if statements that make it hard to debug. I’d suggest rewriting it like this and using indentation to make it easier to see what is going on at a glance:

if (is_page(esc_url( wp_get_current_url() . '/?sortby=asc'))) {
    if ( $newQuery->have_posts() ) { 
        while ( $newQuery->have_posts() ) {
            $newQuery->the_post();
        }   
    }
} else { 
    if (is_page(esc_url( wp_get_current_url() . '/?sortby=desc'))) {
        if ( $newQuery->have_posts() ) {
            while ( $newQuery->have_posts() ) {
                $newQuery->the_post();
            }
        }
    } else { 
        if (have_posts()) {
            while (have_posts()) {
                the_post();
            }
        }
    }
}

An editor with syntax highlighting, like VSCode for example, also makes this a lot easier — it changes pairs of bracket colors so that they match.

There are some other problems in the code, though:

• As @ddur mentioned is_page() is also used incorrectly, you can see this answer for more details (which you’ve already seen).
• You could use else if to simplify these nested if statements quite a lot and make it easier to read
• Those echo statements don’t work the way you think, see the code above instead