Geekbench allows you to measure your device's performance by running a benchmark, which assigns work to your device and evaluates your device's ability to complete it.
The Geekbench Score is useful for comparing different devices quickly. Depending on the platform you're using, there may be some scores provided in the application to compare your result to, and you can also take a look at the Geekbench Browser (https://browser.geekbench.com) for individual results or for average results on the Benchmark Charts. When comparing scores, remember that higher scores are better and that double the score indicates double the performance.
In regards to the downloading the current version of Geekbench 4, is it failing to download initially? Or is it downloading but failing to launch? Also, which device and operating system version are you using?