I think Para in this sentence would translate more to "in order to" rather than "so that I can." So it would be "I am only here (in order) to observe." Although I am not sure who you are responding to. If you are responding to SMA Gringo, who was responding to Andy Lewis, then I think you are right, Ser observar would mean "to be seen (or observed)."
i translated the above sample sentence as "Im here alone in order to observe." I was marked incorrect. I knew that Duolingo wanted "Solo" to mean "only", but i thought id see if "alone" worked. How would i say "Im here alone in order to observe." To sum up...does SOLO mean "alone" in certain sentences?
Oddly, in just about every other language, the accent mark is called a tilde.
See rule #1 of the following link:
"I am only here to observe" actually has a misplaced modifier. "Only" should be after "here" ("only to observe"), not before it ("only here"). "Only here" implies "just here, not there". This is a common error in English. A better sentence is "I am here only to observe."