Once I connect to wifi software updates & goes back to "let's get started"

This is usually caused by an insufficient power supply.  If you received a USB power adapter with the device (it would help to know the model number written on the Roku device), use it.  If it's the Express that doesn't come with a USB power adapter, make sure the one you're using can supply at least 1 Amp.  Look at the fine print for something like, Output: 5V 1A.  Anything greater than 1A (or 1000mA) is OK.  Note that some TVs with USB ports cannot supply enough power.