To the extent that the conversations and evidence you want is part of the court record, these are generally considered "for public inspection". You can go to the court house and view the file for free usually, or you can request a copy. Most courts charge a per-page copy charge (I've seen $0.25 to $1.00 per page, depending on the court.) Whether you can file the request by phone/fax/etc. is going to depend on the court. Just call them and tell them you'd like a copy of your previous file and ask them what options they offer. (Don't give them a bunch of background - it's a waste of time - they provide copies of files every day to people and attorneys - just tell them you need a copy and they'll let you know how you can get it.)
To the extent that there is evidence or notes from your previous attorney that were not made part of the court record, you'll need to call their office to get that. Again, this is a very normal, daily request that we attorneys get. As long as you don't have a balance due to the attorney, they should provide you with a complete copy of your file. Again, they may charge you a copy fee. (And if you due have a balance due, don't let that stop you. Call and ask anyway. Sometimes we're glad to know a person has new representation and the attorney may work with you to get you the file.)
For records that a police station would have but your previous attorney never got, you can file a FOIA request. I've done this for fingerprint reports before.