The 2000 watt inverter/charger (SKU: R-INVT-PCL1-30111S)on the Renogy website has a 30 amp internal transfer switch. No mention if it is new. There is a 2000 watt inverter (SKU: R-INVT-PGH1-20111S) new
addition that is just a inverter.
The documentation on the Renogy site leaves a lot to be desired, there is no general installation instructions. I believe there is a circuit breaker in the unit but it is vague at best . In most cases with a unit like that with the assumption that you have a 30 amp shore power service going to a 30 amp main breaker you would put the inverter between the two. The outlets could come of of your 15 amp branch circuits. In all cases if you are not comfortable with AC wiring, I would get a hold of an electrician.
I would also ask Renogy for a detailed installation document, or demand my money back. If they can't support their products they should not be selling them. I would expect some data on wire size and fusing on the DC side.
I do have a post with general information on fusing
with a inverter example.
The remote on/of switch is a convenience item, the inverter left on will use a minimal of 15 watts. If it is difficult to get top the main off/on switch (most installations) then the remote can be placed where it easy to access.