What you want to do is not possible with pagination. I've been thinking about it and came up with this.

This is how I will do it

- Get the current page you are on with `$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;`

- Run a custom query in which you get the first post, which will most probably be the newest one. 

- Do a check to see if you are on page 1, if yes, execute this custom query, if not, do execute this custom query

OK, this is part one. Here is the code

    <?php
    $paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
    
    if( 1 == $paged ) {
    
    	$args1 = array(
    		'post_type' => 'my_post_type',
    		'post_status' => 'publish',
    		'posts_per_page' => 1,
    		'ignore_sticky_posts' => -1, // remove sticky post
    		'tax_query' => array(
    			array(
    				'taxonomy' => 'my_taxo',
    				'field' => 'slug',
    				'terms' => array('slug1', 'slug2', 'slug3')
    			)
    		)
    	);
    
    	$post1 = new WP_Query( $args1 );
    
    	if ( $post1->have_posts() ) : 
    
    		while ( $post1->have_posts() ) : $post1->the_post(); 
    	
    			//YOUR LOOP ELEMENTS GOES HERE
    	
    		endwhile; 
    		wp_reset_postdata(); 
    	endif; 
    	
    }
    ?>

Now come the tough part. `offset` is one of the anti-user-friendly parameters to work with. I believe that you are on the homepage from what I can gather. So I'm going to handle this as if you are.

Here is how this will work

- First of all, I would completely drop the custom query and revert back to the default loop on the homepage. It will makes things more easier and is the more correct way of doing things. Also you will not need any other parameters to set for pagination to work correctly, you can just use default pagination

- Use [`pre_get_posts`][1] to alter the main query accordingly to set your term on the homepage

- Together with this, still inside `pre_get_posts` set your `offset`

- You'll also need to subtract your offset from `found_posts` otherwise your pagination will not work correctly

So, on your homepage you will have

    <?php
		
			if ( have_posts() ) :
				// Start the Loop.
				while ( have_posts() ) : the_post();
			
					///<---YOUR LOOP--->
			
				endwhile;
					
					//<---YOUR PAGINATION--->	
					
				else : 

					//NO POSTS FOUND ORSOMETHING	
					
				endif; 
				
		?>

Now, the following code will go into functions.php. This is a heavily modified version of code found in [this answer][2] from  [its_me][3],my own code and your code

    function tax_and_offset_homepage( $query ) {
        $offset = 1;
        $ppp = get_option( 'posts_per_page' );
        $paged = $query->query_vars[ 'paged' ];
    
        if( $query->is_home() && $query->is_main_query() ) {
    		$query->set( 'post_type', 'my_post_type' );
    		$query->set( 'post_status', 'publish' );
    		$query->set( 'ignore_sticky_posts', '-1' );
    		$tax_query => array(
    			array(
    				'taxonomy' => 'my_taxo',
    				'field' => 'slug',
    				'terms' => array('slug1', 'slug2', 'slug3')
    			)
    		)
    		$query->set( 'tax_query', $tax_query );
            if( !is_paged() ) {
    
                $query->set( 'offset', $offset );
    
            } else {
    
                $paged_offset = $offset + ( ($paged - 1) * $ppp );
                $query->set( 'offset', $paged_offset );
    
            }
        }
    }
    add_action( 'pre_get_posts', 'tax_and_offset_homepage' );
    
    function homepage_offset_pagination( $found_posts, $query ) {
        $offset = 1;
    
        if( $query->is_home() && $query->is_main_query() ) {
            return( $found_posts - $offset );
        }
    }
    add_filter( 'found_posts', 'homepage_offset_pagination', 10, 2 );

This should give you a basic idea on how to solve your problem. Please feel free to modify all these code to suite your needs

  [1]: http://codex.wordpress.org/Plugin_API/Action_Reference/pre_get_posts
  [2]: http://wordpress.stackexchange.com/a/124426/31545
  [3]: http://wordpress.stackexchange.com/users/10691/its-me