If you do not see the subscribe button on the forum view then it will be because it needs adding to the theme template. The codex on the subscriptions plugin will, I believe, document this.
But… at forum level – your users can also subscribe to forums using the SP profile where they can check on the ones they want to subscribe to.

So am i putting this code which i found here: http://codex.simple-press.com/codex/plugins/our-plugins/available-plugins/subscriptions/

sp_SubscriptionsSubscribeForumButton('tagClass=spSubscriptionsSubscribeForumButton spButton spRight', 'Subscribe', 'UnSubscribe', 'Subscribe to this forum', 'UnSubscribe from this forum');

in my spForumView.php of my theme?  How does this work? Where do i put it?

(It would be useful if you could use the code button on the toolbar when pasting program code – thanks)

The thing about template driven displays is that you out things where you want them. if you look at the forum view template and follow it down logically you will see that it follows what you see on your display. The names of functions are, hopefully, pretty explanatory.

What you might want to do is put it in the same place as the topic subscription button on the topic view so it might be worth looking at that and then selecting the same spot for the forum button.

Sorry

So am i in the right place.  Do that in the spForumView.php?

Yes- forum View is the display of a list of topics specific to an individual form.

thanks

In the subscriptions option if I enable “auto subscribe members to all topics they post in” will they be able to unsubscribe to that topic in the future if they wanted to?  Also if I enable that feature now does that effect only the new topics or the old ones as well?

Thanks for your help

As it says in the notice at the top and in the popup help – it will only effect new user registrants. Existing users will need to visit their SP profile to turn the option on.
And yes – they will be able to unsubscribe from any topic as is normal.