Hi:
Below is the link to the Crucial memory report for your model notebook.
https://www.crucial.com/compatible-upgrade-for/hp---compaq/pavilion-14-bf102tx
It has two memory slots and each slot can take a max of an 8 GB memory module.
Your notebook's processor can't run the memory any faster than 2400 MHz, so you would be fine with that speed.
You can also check what speed the current memory chip your notebook has and buy one of the same speed.
HP may have installed a DDR4-2666 MHz chip in there. Those would automatically bridge to 2400 MHz.
While many notebooks with two memory slots and an Intel 8th gen core processor can support a 16 GB memory chip in each slot, both the above report and the service manual indicate the max is 8 GB per slot.
So, if you want to experiment with a 16 GB chip, it would be a bit risky to do so.
Below is the link to the service manual.
http://h10032.www1.hp.com/ctg/Manual/c05527168