For the first sentence, it would be the same sentence, or it might be re-formulated in this manner: يوجد مطعم جديد هناك (which I think is better for the first sentence of yours). Here we used the verb يوجد meaning "exists" and we moved "Hunák" (meaning there) to the end of the sentence to signify a place.
For the second sentence of yours, it's the same sentence with يوجد but replace Hunák with Huná (here).
To what I know, in English when you start with (there is) it is usually taken to be (exists) and not pointing to a location. Unless you move (there) after the verb (to be) then that would make it a predicate and hence an item of information to be told: a new restaurant is there.
هناك مطعم جديد merely means a new restaurant exists UNLESS the context signifies otherwise maybe. Typically pointing to locate something is done after the object to be located. In contrast, pointing to identify (i.e. this and that) which are هذا، ذاك، تلك، هذه (all these and more) are typically placed before the object. But again, the context can also modify these a bit.