Or better yet, Just try to solder 2 wires together or a wire to a small piece of metal. Cheaper, more effective, and you will learn easier without the thought of maybe ruining something.
My first soldering experiment was on my truck. Had some break light issues. Come to find out someone that owned it before I did had done a horrible splicing job. So I soldered all the bad wires back together. Haven't had any issues since.
Since then, I've done many battery replacements in SNES, NES, GB, and GBA carts. A Sega CD fuse relocation mod, LED mods, ETC…..