Hey there!
You change the spawn locations in your [maps] folder, either fivem-map-skater or fivem-map-hipster, depends on which one you’re using 
There you will find all the spawn locations, simply remove all except for 1 you wan’t to use. Here you can find some spawn locations that you can use or download this resource which lets you see the coordinates on the top of your screen by using the command /coords. If you have any more questions I will try to answer them to the best of my knowledge.