"We are having lunch and we are talking here."
Translation:Itt ebédelünk és beszélgetünk.
There is no significant difference in it, both can be used in every situation. The only slight difference lies in the fact that Hungarian is a very expressive language and there are many methods to nuance things. For example, in this case, "beszélni" expresses something constant, not interrupted, while "beszélgetni" marks the verb as expressing something interrupted, something that isn't done in a straight line, constantly. This aspect of the language doesn't really matters in the case of this verb, but there other verbs in which the -get/gat suffix really makes a difference, like the verb "menni", meaning "to go", which in 3rd person is "megyen" (or "megy", is the same) and addig the -get turns into "meneget". "Megy' expresses the normal act of going somewhere, while "meneget" expresses the act of going somewhere, but occasionally stopping then continuing again and so on, basically something that's not constant. As I said "beszelni" is not that much of a case. Sorry for making this long :)
(Frequentative suffix) Mostly added to transitive verbs (less frequently to other types of words) to form new verbs denoting repetitive action. It may also change the meaning: beszél (“to talk”) → beszélget (“to chit-chat”)
Whilst the citation above partly provides an answer to your question, I believe "beszél" is more often used on a one way street, more similar to "speak", whereas "beszélgetünk" is a closer translation to "talk to somebody", "converse", "chat".*
There is no actual word-order in Hungarian, the word you want to emphasize can be used as the first word or somewhere in the front of the sentence, but that is no error. "itt" cand be used anywhere. I am actually noticing that Duolingo hasn't done the Hungarian language well, as there are lots of problems