Of course, you need to begin this process at least a month, if not more, before you plan to actually move. Three months won't be too long if you also intend to have a yard sale. Three months is not long at all if you are planning to do most of your own packing. You may be surprised how long it really takes to pack everything yourself.
You also have to allow the house moving companies the time to work up a correct estimate for you. One thing that moving companies may do differently is how they intend to move anything very large or awkward, such as spa or ATVs or other awkward sports equipment. Or if you intend to have them transport your car instead of driving it. A dedicated moving company will work with you on how they plan to transport these items. Whereas a moving company just in it to make money may sort of blow it off and when it comes to the moving day you may be stuck finding different transportation for these items.
If you do have a lot of awkward items, not refrigerators or washer and dryer units, but things like a very large wrought iron old fashioned porch swing that have to be dismantled and even when dismantled is still awkward. Or various motorized items like ATVs or dirt bikes or other bulky items which are rather light in weight for the amount of space they will take up in the moving van. The moving company will generally assess a bulky article charge or even assess a weight additive based on the length of the item. You need to make sure the movers see these items when they do the initial walk through for your estimate because a dedicated mover will want you to understand what the additional costs will be for those items.
If you decide that you want the movers to move your vehicle they will have two different ways they can do that. If the vehicle is small enough such as a Smart Car and the moving van is big enough a dedicated mover will allow the vehicle to be driven into the van and then it is secured within the van. If you do this make sure you leave as little gas in it as possible because even a gallon of gas equals more cost to you. A gallon of gas weight a little over six pounds so you will be paying for six pounds of weight for each gallon you leave in the vehicle. This includes any ATVs or other motorized vehicles that are being hauled.
