how to make first post diffrent than other posts?

Maybe you can use wp-sticky?

I would just add a counter variable before the loop equal to 0 or 1 and just increment the value at the end of the loop and just check if $i == that variable and if so, use different html, otherwise use the standard html.

Or try it with something like this inside the loop:

<?php if( !is_paged() && $wp_query->current_post == 0 ) :  ?>
<p>This is the first post</p>
<?php else : ?>
<p>all other posts</p>
<?php endif; ?>

hmm how would it look in my code so i dont mess up the catagories like show me that with my code inside it thanx

like how would i enter it depending on my code. what do i insert and where do i insert it

my code: https://pastebin.com/BydqqyQy

You have two loops in that template file. get_template_part('content', 'page'); gets the first loop.

I have implemented it on the second loop. Try it with this [untested]:
https://pastebin.com/x2N88SFA

awsome thanx!! it worked! only one problem im running into with my thumnails not being the diffrent sizes that i want them to be

here is my html:
First post:<center><div class="art-article img"><div class="attachment-post-thumbnail"> <?php the_post_thumbnail(); ?></div></div>

Rest of the posts: <div class="art-article img"><div class="attachment-post2-thumbnail"> <?php the_post_thumbnail(); ?></div></div>

my css: `.attachment-post-thumbnail {
width:450px;
height:300px;
}

.attachment-post2-thumbnail {
float:right;
width:90px;
height:90px;
}`

and my funcion that i am using is:

add_theme_support( 'post-thumbnails' );

what do i have to do to make the change of different sizes to happen?

review:
https://codex.www.ads-software.com/Post_Thumbnails
https://codex.www.ads-software.com/Function_Reference/set_post_thumbnail_size
https://codex.www.ads-software.com/Function_Reference/add_image_size
https://codex.www.ads-software.com/Function_Reference/the_post_thumbnail