I don't know about the spec of the box from Aldi, but if you want to pick up Freesat, you do need a satellite dish.
Even though you have a wall socket marked SAT, it doesn't mean there is a dish on your community.
Our community paid for a large dish and we all connected to it for about 200€ each, this was a discounted price as we joined en mass so to speak.
I bought a Bush box from Argos in the UK for around £49 and it works perfectly in Spain picking up the Freesat channels.
I am not sure if there is BBC world, there are so may channels!
But certainly you get all the usual UK channels and loads of rubbish ones too - Bid TV, etc., etc.,!
hope this helps..............