Lynn, don't worry about asking questions! Yes, probably the way you treated your palm is what caused the crumbling. You need to melt the entire package together, stir it up thoroughly, then pour the amount you need into your soap pot (by weight). Each and every time you use the palm you will have to make sure it is all melted and then mixed thoroughly before you measure out your needed amount. Otherwise you will get too little of the stearic and when you get to the bottom of the bag you will get too much.
It is best and easiest (until you have more practice) to heat your oils and butters before you add the lye. After you have practiced you can let the lye melt your hard oils and you can soap at room temp, but start with heating them. You will want your oils and your lye no more than about 10 degrees apart for the best, easiest results. It sounds like you did check that, so you have that part down.
As for the palm, you want homogenized if you don't want to have to worry about mixing it. I don't use palm at all, so I can't tell you where is best to buy it, but I do know that many of the suppliers also sell it. Just read the description and you will see that it says that it is homogenized and usually it also says something about not having to mix it.
Yes, I think most newbies like the ease of the BB calculator, so try it and see what you think. I would recommend using the same recipe you already used though, and change it to a one pound recipe (in grams) and make that one again. There is nothing wrong with sticking with one recipe and trying different things. Like doing it plain, then adding a color, then adding a fragrance, then a fragrance and a color, changing the super fat, etc. Practice is the only way you will learn and experience the different things that can happen. Look at this first batch as a learning experience and know that you will have more. I have been soaping for more than 30 years and still have learning experiences on occasion. It is the nature of the beast !