Translation:Are there two?
Might find helpful : Adding つ to Kanji of number makes it a general object counter (used for indicating how many objects of a particular kind are there) The pronunciation also change sometimes.
So 一+つ ー> 一つ【Read: ひとつ】 this means one object or one thing
二つ 【read :ふたつ】 two objects or two things
三つ 【みっつ】 three objects
四つ【よっつ】 four objects
六つ 【むっつ】 Six objects
七つ 【ななつ】 Seven objects
八つ 【やっつ】 Eight objects
九つ【ここのつ】 Nine objects
Thr closest english equivalent is how we have "first, second, third, fourth" which almost mean the same thing as "one, two, three, four" but are used in different context. Obviously used differently in Japanese, but it's a comparison. Better than "because that's how it works".
Yeah can confirm, arimasu is a verb, meaning you are describing something that is currently in the act of existing, but is a non-living object. You would describe a chair, for instance, with arimasu. Imasu is a verb used to describe living things, so you could say "there are two dogs" and you would use "imasu" at the end. You would say desu at the end if you were describing something that happened, for example.