For light use such as web browsing, streaming, office apps etc, you don’t need top tier specs just something reliable.
Something at lest with a processor of a intel Core i5 but if you want to install windows 11 you need to research the model and generation of the CPU as not all support windows 11.
At least 8GB ram
A SSD is a good thing to consider as the PC will not only boot up faster but it will also load up programs more faster compared to a HDD.
You can keep these specifications in mind when searching for one.
What resolution does the monitor support? If it supports 1080p or higher, and you want that resolution, then you will need a desktop that does manage to output the display in that quality.