GeekBench only costs money if you want to do things like hide your results from the world instead of putting it on their score aggregate list - only really useful if you're reviewing embargo hardware. Otherwise Geekbench is free.
For CPU there's also Cinebench which is widely considered good for testing heavily threaded apps and sustained performance under a heavy load with respect to thermals and boosting limitations.
For disk there's BlackMagic's disk speed test on the Mac App Store - they also have one that tests general speed I think but I've only used their disk test.- It mainly tests raw bandwidth though - if you're looking for more detailed results for latency and other, I actually don't know any good tools other than AIDA64 which is probably not a candidate here. Don't even think it runs natively on macOS. But you're probably most interested in just bandwidth numbers anyway.
RAM will be tested by Geekbench as well - at least for speed. If you're looking for a test of all the RAM chips being fine, memtest86, which is an environment you boot into, can test that. For a less-overhead setup that can be run from within the OS, there's a brew package called memtest, however, due to limitations of testing within an OS you can't really test all available memory, but you can get close enough that you'll get a good feeling that all is well and good.
For GPU, Geekbench has a Metal and OpenCL test. For geometry, TMU, etc. there's Valley and Heaven as standard go-tos. You can also run various in-game benchmarks. Civilization and Tomb Raiders are two examples of titles with a built-in benchmark mode. BruceX is also an oft used Final Cut benchmark, though I would not conflate the numbers from it with real world expectations.
It's important to note that the speed of a computer is not one-dimensional. Even for a single component. You may have a GPU with massive shader processing output, but with barely any TMU performance - Thus this GPU will do amazingly at compute tasks, but it will be horrendous at texturing things for a game. A balanced benchmark requires pushing a lot of different workloads at a system, and I would advice reading Anandtech and watching Gamers Nexus for further details. Both are thorough in their descriptions of how they do their benchmarking
