Hello, My name is***** will do my best to help you on this question.
Did the unit only come with a USB cable no wall AC charger ?
Answer to your 1- You can buy a universal wall charger for $29 from the website. Here is the link.
Honestly if you have any USB charger for the phones at home like iphone or anther andriod phones you don't need to buy the charger use those charges with the cable supplied. that should work perfectly fine.
You device comes factory pre-loaded with 35,000 courses world wide with all the basic features you don't need any membership or sync to do that.
I hope this answer your question. Please let me know if i missed something or you need any further assistance. Please don't forget to rate/accept the answer. Thanks and Happy Holidays.