Learn English – A word for someone who shows great interest/love for something that they know very little about

Perhaps

pushover - a person who is easy to overcome or influence: Colonel Moore was benevolent but no pushover

or

patsy - a person who is easily taken advantage of, especially by being cheated or blamed for something

or

soft touch - (informal) a person easily persuaded or imposed on, esp to lend money

Of the three, the last is probably the most positive (at least in US usage). The other two suggest gullibility.

Consider mocking:

showing that you think someone or something is stupid

(Macmillan Dictionary)

Or sneerer:

sneerer: a person who expresses contempt by remarks or facial expression

(WordNet)

Depending on the context, elitist might fit as well. An elitist community may flaunt its superiority by being unfriendly or mean to newcomers (hence sneer at their questions, ridicule, etc.).