Attached below please find Common Core standards for math and reading/language arts/writing written in student friendly/parent friendly language. This is from the Teacher's Hero site.
This will be a starting point for you to write your own "we can" or "I can" statements for posting in your room. This really should be done as a result of "unpacking" each standard, going to Bloom's or Webb's Depth of Knowledge, and considering the verbs within the standards. Also, each standard should have an "I can" for the basic skill set. the mastery skill set. and beyond mastery (enrichment).