Indeed this double triggering is not normal, to get rid of that you have several solutions,
First I would suggest that you unplug the power of the Erae and take some time to gently rub the surface with you palm around the concerned area. That allows to release the tension of the silicone that could have been created with transportation. Then plug the power again and let the calibration happen without touching it, that correspond to the ripple effect that happen at the start.
Otherwise you have two temporary options, first reproduce the double triggering and then click simultaneously on the Alt and - buttons. The Erae Touch turn in black with little white + sign. That correspond to the last places the Erae was triggered. Select the unwanted spot that has been triggered, it'll turn red, then tap on it a second time to confirm the selection and delete it. Click on the Menu button to go back to your layout.
This adjusts the sensitivity of that location, however it will be reset if you restart the Erae.
Another way is to click simultaneously on the menu and - button. You will see a quick ripple that correspond to a quick calibration above the one at the start. That can get rid of the ghost note without having to start the Erae again. This will also be reset by a power cycle.
If none of those solution works for you we can replace it
Concerning the second issue, by default the sequencer is on external clock so if you don't have a clock coming from a DAW for example, the sequencer will not launch. To go to an internal clock, click on the blue + sign on the top right corner to go to the sequencer menu, click on ext. From there you can define your internal BPM by pressing + or -. The scrolling speed of value depend on the pressure you apply on + or -. Click on the red X cross to go back to the sequencer. To learn more about the sequencer you can watch our video about it
Tell me if that solve your problem or if you need anything else
Have a nice day,