Travelling with conditional green card for 1 week.

[tenfour]

Hi there, i need help regarding a trip i have in about a week from now.
I got my 2 years green card 5months ago and am planning to go to canada for 7days.
everybody i know has been discouraging me to go on the trip due to issues with re-entry into the US.
Got my green card based on marriage, and i never overstayed on my visit visa before then.
have got $1000 cash with me for the trip which i don't intend on spending since i already got my ticket and am staying with a cousin for the 1week duration.
am currently working with about $2200 a month. Although my credit card is maxed out, but have got $1000 with me just incase.
Is there anything i should be worried about/ questions to expect upon re-entry and what documents do i need to present on re-entry other than my passport and green card.
Plus do i need to apply for a ETA (Electronic Travel Authorization) to get into canada even though i have a green card?

[newacct]

You need eTA if entering Canada by air. You don't need eTA if entering Canada by land. Other than that, your green card and passport should be enough.