HELP!!

I’m a beginner and I’m looking to get a good mountain bike which we’ll suit me now and will be good for me to grow into as well. There’s two bikes on sale that caught my eye for the price. The first is a Grand Canyon 5 for roughly $500-600 and the second is a Polygon D5 for roughly $700-800. Things I like from the Canyon is that it’s cheaper, has 29” wheels, and it has a SHIMANO Deore 12s. The Polygon has a SHIMANO Alivio 9s but I like that it has full suspension unlike the Canyon and with 120 travel instead of 100 from the Canyon but it has 27.5 wheels. There’s other spec differences that I’m not sure what they fully mean. Anybody know anything about these two bikes and which would be better? Or any other bikes other than these. I’m trying to take advantage of these Black Friday/Cyber Monday deals so my time is limited on deciding. Thanks for the help!