Do museums have audience (line 4)? It may well be the term used in the area, in which case use it, but I would talk of visitors.
L5- typo: I have realizad (-ed)
L7- continuously to upgrade their knowledge and appreciation of art- I'd move continuously to after art, but others wouldn't
L8- typo- contemporary (n missing)
l12- My inmediate responsabilities- immediate responsibilities (this mistake is repeated)
l16- perusing the 19th and 20th century works- I'd change persuing because it sounds a bit casual- examining or something?
l18 coordinator position of the MNCARS- I'd use 'for'
l19 as a As a- repeat- There should be a full stop before it IMO
l27 correspondence with public museums and private collector- singular?
Para 3- In addition to my written abilities- I'm not sure what you mean here- abilities that have been recorded or with the written word? If the latter, then I'd use writing skills. Also the phrase doesn't seem to connect to me tothe rest of the sentence- I don't see the connection
foundation for the development and support of contemporary art- a/the foundation