Wooden mallets are mostly used for hitting your chisels when cutting joints (like dovetail joints or chopping mortises). You should never hit a chisel with a metal hammer. Build or buy a mallet that is made of fairly hard wood (e.g. maple, oak, beech wood, etc.), that will feel well balanced in your hand, and that gives you enough weight to chop with your chisels.
now I finally know what to recommend my friends when I try to convince them to give handtools a try (I currently am doing an apprenticeship in cabinetmaking (unfortunately mostly particle board) and said friends they do the same and often have no clue what can be achieved with handtools alone) because up until now, I never knew what to recommend for sharpening as my setup is great but very expensive. And I guess if I recommend to get two stones instead of a combination stone, one can keep one side flat for flattening the backs of new chisels, and add a strop with some polishing compound I really can’t think of anything else one would need for a long time!