The proofs in real analysis are a lot different than what you proved in LA. you did well in LA which is good since it gets you in the mindset to start doing proofs. I took a graduate class on linear algebra (which you could consider advance linear algebra) and it is a lot harder than the undergraduate version. Real mathematicians hardly ever use matrices and you will probably not use any matrices in advanced linear algebra. Instead you will use the more abstract version-the linear transformation. here are some ideas that you will encounter in real analysis, see if you can follow what is going on:
-read the idea of what a cauchy definition is of a continuous function
http://en.wikipedia.org/wiki/Continuous_function
-here is what a cauchy sequence is. real numbers can be defined as a cauchy sequence, so you will be doing a ton of these.
http://en.wikipedia.org/wiki/Cauchy_sequence
-here is an epsilon-delta proof. you will be doing a TON of these proofs. this is probably the only thing you must read in this thread if you are going to take analysis
http://mathworld.wolfram.com/Epsilon-DeltaProof.html