website forwarding

[#1]

Excuse my ignorance!
I've a site set up on PrestaShop. I want to point the domain name I've got with plusnet to that site. 
Just not sure what I need to do, been going through their FAQ's and read thread about CNAME etc. in domain name settings but a little confused.  
Will there be a delay in forwarding from setting up too?

Thanks in anticipation

[#2]

Be careful. A CNAME is not the same as a forward.

If you have domain.com and your prestashop is prestashop/domain

You can't simply make a CNAME as the packets will arrive at the IP for prestashop/domain looking for domain.com

You should be able to create a permanent forward (401 redirect?) to the URL you want.

[#3]

Thanks for your reply.

how do I create a permanent forward (401 redirect?) to the URL i want?

[#4]

If you are using Linux based hosting, it's recommended to use a 301 redirect. This will allow Search Engines to follow to your new domain/folder as if it were. 

See: https://www.inmotionhosting.com/support/website/redirects/setting-up-a-301-permanent-redirect-via-ht...

If you need any assistance, don't hesitate. It might be better to understand your current set up to give the best solution for you.