Ok so i heard about pretendo last week and downloaded it today and i tried all day to figure how to use it, i think that i managed to link my pnid but when i tried to use online services it didnt worked, i tried to use it to download mh4u dlcs but i keep getting an error message, i also tried to get on the eshop and i got the same error code. I just want to know if i need to do something else to make it work or if i’ve done something wrong(im just clueless abt how or what do i have to do with pretendo i just need help 
).
Can you please provide some more information on this? Do you get any error codes?
Pretendo doesn’t support the eShop.
Are you on Wii U or 3DS first of all?
If you’re on 3DS, try switching to Nintendo, then back to Pretendo, however, if you’re on Wii U, it should work fine?
Pretendo doesn’t support the eShop
For MH4U DLCs, you need to use a DNS redirection then remove it to go back to Pretendo online proper.
“Online play is working with added support to play with MH4G. Download server requires for Downloadable Content (DLC) DNS redirect (DNS: 34.75.107.68). Note: this DNS service is unaffiliated with Pretendo.” from: Pretendo Game Support Status [Unofficial Pretendo Wiki]
When on Pretendo, Nintendo Network will not work (including the eshop) as the servers are different.