how do i know if this is compatible with the pc i already own? sorry new to this stuff

Check for m.2 pci-e 5 compatibility on your motherboard

Questions & Answers: WD_BLACK SN8100 NVMe SSD - 4TB, With Heatsink, M.2 2280 PCI-Express 5.0x4 Internal Solid State Drive (SSD), Up to 14900 MBps Read -WDS400T1XHM-00CMT0

double click image to zoom in

WD_BLACK SN8100 NVMe SSD - 4TB, With Heatsink, M.2 2280 PCI-Express 5.0x4 Internal Solid State Drive (SSD), Up to 14900 MBps Read -WDS400T1XHM-00CMT0

EXPERIENCE PCIe Gen 5: Drastically enhance your gaming and content creation experience with this PCIe Gen 5.0x4 NVMe M.2 SSD.
BLISTERING SPEEDS. IMMENSE CAPACITIES. Your drive reaches sequential read speeds up to an astonishing 14,900MB/s, sequential write speeds up to 14,000MB/s, and over 2,300,000 IOPS of random performance (2TB – 4TB models) and offers up to 8TB of capacity.
EXTENDED ELEVATED PERFORMANCE. With its custom heatsink, the WD_BLACK SN8100 SSD delivers up to 15x longer sustained performance under heavy workloads compared to the non-heatsink version.
SPEED MEETS RELIABILITY. Enjoy heightened speed and reliability with up to 4,800 TBW (8TB model) endurance and our latest TLC 3D CBA NAND technology.
CUSTOM WD_BLACK HEATSINK. The custom WD_BLACK heatsink is the lowest profile option on a PCIe 5.0 drive with RGB lighting. Made from anodized aluminum, it delivers silent, fanless cooling and customizable lighting to match your build.
POWERED BY SANDISK: The WD_BLACK, WD Blue, and WD Green flash products are manufactured by Sandisk Technologies, Inc. or its affiliates and distributed under license from Western Digital Corporation.