Translation:I need to go to the shop in the afternoon.
"I will go shopping this afternoon" should be accepted. Nothing in the question says anything to the effect of "I need to go." If it is "I need to go" then it should be 我需要, not 我要.
商店 is a place not an action, no where in the sentence did it say he/she wants to do shopping, going to the store might be to meet someone, or return an item, or deliver product, or pay debt, or anything else. So saying "going shopping" should be accepted is just wrong!
Not quite, but almost. "I will go shopping this afternoon" = "下午我要出去 买东西。 " But yes, ""I will go / I want to go" = "我要去" The owl's "I need to go" would be "我需要出去" or something similar.
This could also be "I am going to the store this afternoon." 要 can mean "want," "need," or "going to." Also, the time could go before or after the subject (I have noticed this problem on other items as well).
Surely "in the afternoon i need to go to the shop" should also be acceptable
My answer "I want to go to the store this afternoon" should be a valid answer - native speakers generally assume "this" afternoon/evening if it's not explicitly stated in context or previous conversation that they're talking about a different day
"I want to go to the shop this afternoon" is corrected to "I want to go to the shop in the afternoon." Technically speaking, it doesn't specify "this" but it's the more common English usage.
Chinese need to get a better language way of expressing will, can, need to, and such much more distinctly
Or English need less word for such information that other languages can simplify in a few words. Or you should learn Esperanto hahaha