HI fellow newbie! I just got my 640 today and have Net10 as well.
Use the following to set it up:
Click on Settings > cellular+SIM
Scroll down and click on SIM Settings
I changed my SIM name to Net10, but I don't know that that is necessary.
flipped switch that says Manual Internet APN to on.
Click edit Internet APN
Change APN to tfdata
scroll down, change IP type to IPv4
click SAVE
Click Edit MMS APN
Change APN to tfdata
WAP gateway (URL) - mms3(dot)tracfone(dot)com
WAP gateway port - 80
MMSC (URL) - mms-tf.net
MMSC Port - 80
Maximum MMS Size - 1024
IP Type - IPv4
Hit Save.
That should take care of it.
I have checked and verified mine, so I know they *should* work.
EDIT (I wish to all that is holy that Nations would tie their freaking accounts together - I have several hundred posts on the Blackberry side, but less than 10 here, so it treats me like a newbie... geez louise... I guess I'll be blowing it out here now, since I now have a Win10 tablet AND a Lumia 640...)