Custom Font and Header

No one can help to any great extent without seeing your site first. All I can suggest is that you upload your image (called header.jpg) to your theme’s images folder and then replace <h1><a href="<?php echo get_option('home'); ?>/"><?php bloginfo('name'); ?></a></h1> with <h1><a href="<?php echo get_option('home'); ?>/"><img src="<?php bloginfo('stylesheet_directory'); ?>/images/header.jpg" alt="<?php bloginfo('name'); ?>" /></a></h1>.

Also, for my tagline I want it to be animated (like a fly-in effect).

You’ll either need to create an animated gif or a flash file, upload it to your theme’s images folder and embed it in place of <?php bloginfo('description'); ?>.

Last questions: Do you know how to create an animated gif file? Also, I have found a custom theme from another site I would like to use. Provided I have all the necessary files, can I use this theme for wordpress? Below is my site, I haven’t done anything with it yet but hopefully it will give you more insight as to my header question. For the theme I want to use, I want the header visuals to stay however I want the title to be in a different font. Thank you for all your help!!

https://www.big-nasty.com

Do you know how to create an animated gif file?

I know – yes. But then you do need a special graphics application to put one together. Flash is becoming more common for animation these days but again, you do need a Flash application to create such a header.

Also, I have found a custom theme from another site I would like to use. Provided I have all the necessary files, can I use this theme for wordpress?

Provided the theme is freely available for use or you have permission to use it, yes.