Motorola A630

i like many people purchased this phone for its text messaging feature. i owned and loved a talkabout. this phone is full of potential, its just so difficult to initialy set up ☹️ ive worked though the phonebook and setting. my issue is with recieving texts. all my TM come with a #. for instance mine is 500. so my first incoming TM is 501, then the next is 502 ect..... wtf!? am i completly missing something with text messaging?? ive only been outa the loop for 6 months lol.