1) Whenever you feel like your games freeze often or your cart malfunctions, format your micro sd card with the
panasonic sd formatter (
guide here). Since your micro sd card is new, you won't have to worry about this now though.
2) Bootloader updaters can be used to bypass any block that nintendo has incorporated on a dsi/3ds. You can download them at
acekard's official website.
Here's an in-depth gabatemp wiki article on updating your cart's bootloader. Since it's posted on the 3ds section, I assume you'll probably need this.
3) acekard 2i uses an unofficial firmware called AKAIO (AceKard All In One), which acts as a loader to load games/homebrews (higher the firmware, higher the compatibility to newer games). It also gives ak2i its UI to navigate through directories using the DS.
Here's the official akaio forums, and
here's the latest akaio release. Just place the "_aio" folder + "akmenu4.nds" onto the root of your micro sd card.
That's pretty much all you need to know to set-up an ak2i. Make sure you bookmark the useful links.
EDIT: since you're already on v3.0.0-6, you will need another ds system (preferably a ds phat/lite) to update. A dsi/3ds is also fine, as long as your ak2i is fully functional on them (meaning, your dsi/3ds has a firmware that is low enough for your ak2i to run on). Ask if you have any questions.