SMART mentioned above is built into every new HDD and SSD. The vendor will typically include a utility specific to their product to accurately report the drive health and stats. Generic utilities can be used but aren't always accurate across all vendor products.
Samsung 850/860 or Crucial MX500 (those are model numbers not size) for internal consumer SSD. Samsung, Seagate or WD, whatever you can get a good deal on for external. I prefer spinning for external but there are pros/cons to each. Environment, longevity, durability, etc.
I've had issue with the Crucial copy software so Samsung may be best for a neophyte.
I catch them when they're on sale. Use camelcamelcamel to check and watch price history.
Once Onedrive is sync'd, there's not so much traffic to be concerned with and you don't have to retrieve files from the cloud to use locally, it just keeps things in sync. It also does versioning so if you do get hit with a virus or cryptolocker, your versioned files in Onedrive should be safe and recoverable.