Activate APN

Hi Community, I have just joined SMARTY and as part of the set-up/activation of my SIM, the instructions suggests that to use your phone in EU, you need to set/activate the APN.

Can I set mine up now even though I am not yet planning to travel to the EU? I thought it might just be best to do it now so that in the future when I do travel, it's already set up and I do not need to do it again. 

Does this affect my plan and services from SMARTY while I am in the UK and not in EU?

My plan is the unlimited plan. 

Thanks very much in advance of you guidance and advice