A link to your site in this thread wound be helpful, I'll try to make some guess based on what you've written, hopefully they'll be lucky guesses... 
saburuko wrote:
It was a clean install from RL, the template does is there but when I click through it's just writing and not the usual menu, there is also this
Menus: Cannot assign default template.
Do you have SEF enabled? IF so is it configure properly? 'White pages' as you've described are usually due to incorrect SEF configuration.
'Cannot assign default template.' This is completely normal, this message will appear in the Template Manager for any template that is assigned as the default. You can only assign Menus to other templates that are not the default. (you can check this by going to the Template Manager and selecting another template, you will see options to assign Menus.)
saburuko wrote:
tbh ever since Rocket started using Gantry I have never been able to upload a template, I let my membership lapse because of it and only recently came back thinking it might work again but to no avail, unfortunately my skill set is not that high
By 'upload' I assume you mean install, or use a RL to do a clean install with a RL package. The gantry templates, and even some of the non-Gantry templates have higher system requirements than a stock Joomla install or 'other' templates.
(I recently installed over 40 RT templates on localhost and install each month's template on a test server and have yet to have a problem.)
That being said, 99.9% of installations issues are due to servers (hosting) that does not meet the requirements for a particular template.
For Gantry templates, you need to be running php 5.2.x or higher with a suggested php.ini limit of 32 MB, optimally 64MB.
You can check your current setting through the Joomla admin page.
Help > System Info > PHP Information >
The php version will be at the top, scroll down the page and look for 'memory_limit'
If you happen to be running php4, or your memory limit is too low, you should be able to change these setting in your host's CP, if not, ask them to do it for you.
saburuko wrote:
This is what I get on my website
Welcome to the Frontpage in bold letters
Either:
1. Admin > Site > Global Configuration : Site Title
2. Menu Manager > mainmenu > Menu Items > Home > Parameters > System > Page Title
3. Content > Frontpage Manager > Content Item > Title
4. Content > Static Content > Content Item > Title
5. Content > Article Manager > Article > Title
6. In your 3rd party SEF component configuration
Probably #2