How do I get the tag to automatically combine 2 fields. Say title & Album: eg. title name (album name) I've tried tag tag but it doesn't activate
Unfortunately, you do not show us what you tried so far.
For me, it works over here:

(All looks a bit like this problem:
Unfortunatly when I press OK and my settings are exactly like picture, nothing happens.
Now, a screenshot would be nice.
Because, as you can see in my attempt, the preview shows that something would happen.
Please note that the filename is not the title.

but when I hit OK. nothing happens to the file
Please check the extended tags dialogue Alt-T which should show that you have now created a user-defined field called TITLE (COMPOSER).
What happens if you try my suggestion?
the field appears, but it doesn't change the title field tag info to include TITLE (COMPOSER)
Let me see:
You originally asked for:
and you got a suggestion for that.
Now you ask for something different, it seems:
Could you show a screenshot of the extended tags dialogue of a file that you have treated already and that does not behave the way you expected?
I don't believe i am. I am simply trying to find (if it's possible) a way within the software to combine the info from 2 separate fields into one existing field. Merging my Composer field with my Title Field. the tag -tag dialogue appears but when I press OK, it doesn't change anything.
I gave you an example of how to get TITLE and ALBUM into TITLE.
The syntax you applied in your example means that you used the contents of TITLE and COMPOSER to create that to a field called TITLE (COMPOSER) - as 1 name. And that is a different field to the simple TITLE.
For further help it is mandatory that you show the extended tags dialogue for such a file for which you claim that nothing happens.
Press Alt-T to open the extended tags dialogue.
If that is not possible for you, then describe
- the contents of the field TITLE
- the contents of the field COMPOSER
- what you selected as FIeld in Convert>Tag-Tag
- what you entered as Format string in Convert>Tag-Tag.