Apart from asking around, a rough way to get some guidance is to one-quarter fill a screw-topped jar with your ordinary garden soil, and then fill the jar almost full of water. Shake the jar briskly for about two minutes until the soil and the water are all mixed up into a brown liquid. Allow the jar to stand for an hour or so, and the soil will have divided up in the water into its basic constituents. On the top will be floating the decaying vegetable matter (humus) while the heavier particles will have dropped down to show the heaviest, and therefore largest, at the bottom, with the finer at the top. Any very fine particles will still be in suspension in the water, between the floating humus and the stuff on the bottom. The more humus that floats on the top, the more the soil contains, and if not much at all is floating, then it needs a lot added to it as it is obviously short of this substance. You will see from the soil particles which have sunk to the bottom how many are coarse, and how many are finer. The coarse particles are an indication of how sandy the soil is; if there is a fairly even balance between these and the finer ones it denotes a loam. If there are a great deal of very fine particles still in suspension, then the soil almost certainly contains a large proportion of clay.
In practice, however, it will soon become pretty obvious how heavy or light your soil is by the mess your boots get into and the ease (or otherwise) with which it falls off your spade.