Short answer: purchase a SSD external drive with a USB C connector. SSD drives are not all equal. The faster external drives will have an internal NVMe connection rather than a SATA connection.
Cheaper external drives (with mechanical hard drives inside the case) with USB 3 (Type A or C) connections are good for back-up or for simple HD video projects.
Part One of the CDA Premiere Video Editing Course in Moodle has an up to date description of various external hard drives on the market. All Fine Arts students at Concordia have access to this course. Look for it on your Moodle dashboard.