Question Will I need to buy antennas for this?


Welcome to the forums, newcomer!

If it's going into a laptop, no. If you're going to use in a desktop whereby the motherboard doesn't have a prior bundled wireless adapter, then yes. If a motherboard, can you please state the make and model of the board? If you'd like to add the card to a board that doesn't have wireless antenna's you can source laptop antenna's and mount them internally in your chassis.
If it fits in your laptop you can use the antenna in the laptop. They are likely close enough even though the wifi6e runs on 6g. A lot of signal for the 5g band is at the very top already.

It is not like you have many option. It tends to be pretty easy to swap a wifi card. If it fits in the slot it will likely work. Changing antenna especially in newer laptops can be hard. The antenna tend to be near the screen and that part of laptops is like cell phones where you need to use heat to soften the glue. Not worth the risk in most cases.
From what I can tell you can't use that card on your motherboard it does not have the proper type of m.2 least that is from a quick look at the specs.

Just buy a PCIE card with the same chipset. These also come with the antenna in most cases so it tends to be cheaper even if your motherboard supported the m.2 card you linked.