I use Baltic birch in1/8 to 3/4 size, as it is very versatile , good for puzzles, portrait cuttings, One can do a lot with MDF board as it is cheap and cuts easy and there is no grain to deflect the blade a dust mask is a must. I sometimes use it for backer board but it is not a preferred product for me. Construction grade spruce, plne can give provide a lot of enjoyment but fine detail needs special tender handling. Every year I make simple toy cars to give to charities for Christmas distribution to kids that may not have presents.2 X4 and 2X6 spruce and pine are good for this. I like hardwoods such as walnut, maple, cherry, beech, birch , bass are all good and can give beautiful finishes for boxes and shelf sitters. They do get more pricy and into exotics woods that need a second mortgage to purchase. They are all good and have their place so the sky is the limit . practice, learn, study, lots of info on the internet, u tube if you are just starting I suggest you keep it simple.