We suggest using a regular U-100 0.3 mL insulin syringe with half unit markings to withdraw the Lantus from the pen. That way, smaller doses can be used, and the injection process is smoother rather than punching it in.
Home testing is fairly straightforward, though it can take a bit of practice to be successful at first. You'll need an inexpensive meter, matching test strips, and 26-28 gauge lancets. You might try the WalMart ReliOn Confirm, Confirm Micro, or Prime. If you dislike WalMart, use our shopping link above and shop at ADW to get the Arkray USA Glucocard 01 or 01 Mini which are unbranded versions of the Confirm meters.
When you examine the edge of the ear, you can see a small vein running along the outer edge. Between that vein and the edge is where you make a small prick and test a blood droplet. I suggest practicing on an apple and yourself to get a feel for it, before you test your cat.