I have to chime in here and say that it is only used with grapes or juice buckets and not kits. Kit wines are balanced to not use mlb. With real grapes and juice, it will help smooth out the wine, provide other flavors, such as vanilla. Unless you have a need to use it- hold off for now until you learn a bit more of the process and what wines will benefit from it. Realize you can ruin your wine if you handle this stuff wrong. For example if you have a nice wine, but want to sweeten it. You accidentally don't add enough potassium metabisulfite and put some sorbate in so you can sweeten it. It was a bit high in acid while fermenting so you added mlb and let it go to completion. No problem, right? Wrong. Because you didn't add quite enough sulfite, the mlb can begin do grow again a bit. They use the sorbate for food and form geraniol - end of your wine. It smells of rotten geraniums and make your wine so nobody will touch it!
Know what you are getting into before starting to use malolactic bacteria.