A few thoughts:
1: You have chosen a B450 motherboard with a Ryzen 3000 series cpu, just be aware that the motherboard might need a bios update before it will work with that cpu (as the B450 boards came out before the Ryzen 3000 series). If you are going with that motherboard, be sure to contact the seller and ask them to update the bios for you before shipping or you could run into problems. The other solution is to go with a newer B550 based motherboard - they cost a little more but you do get PCIe 4.0 support for future graphics upgrades and they have Ryzen 3000 series support out of the box.
2: That PSU doesn't look great, there are a lot of poor quality PSU's around (and Cooler Master don't actually make them they just re-badge other units so it's difficult to know if it's a good or bad model). There is a good article on Toms with some trusted supplies at different price points:
https://www.tomshardware.com/uk/reviews/best-psus,4229.html
Not listed but the Corsair 'CX-M' units are a pretty good mid range unit, a 600W CX-M would be fine for your build (the 'RM-M' units are higher quality but cost a bit more so it depends on budget).
3: Storage wist I don't think I would go for that combo - if you are going for an SSD you can typically get an M2 based NVME drive for similar money to a Sata ssd (most motherboards support at least one NVME) and these are much faster. I would also say that if you are looking at gaming, running games off a HDD isn't a great idea these days as it can cause very long load times as well as stuttering and visual pop in during game play as data is streamed in. I would personally suggest for the price of the two drives, you should be able to get a single 1TB NVME drive which would be better all round solution and cost a similar amount (albeit with a bit less storage space).
CPU, GPU, Memory and Case all look good.