Hi, I'm new to Wordpress and wonder if there are some plugins which should be set to run globally no matter what?

What about plugins such as Wordpress SEO by Yoast, W3 total cache and what I call admin plugins (P3 plugin profiler, Editorial Calender, Tiny MCE advanced)

How can I fix that one plugin is only loaded on the index page?

Looking forward to your kind reply

thanks for your help