MDL Sampler, Still don't get it

Hey you guys, I'm trying to figure out this whole sampler thing because I am trying to use it for not only Band writing, but for experimental Jazz ensemble too.

The only problem is that I have no Idea how to work it.

I've seen comments, but I am just totally lost on how to get it to work. So I am asking for a kind fellow in the community to possibly do one the following

1. Explain the sampler in a comment like I am 5 years old because I clearly am lost and am still relatively new to the customization side of musescore.

2. If you want to be really really nice it would be amazing if you could make a video explaining the process because again, I have no idea what to do or what I am doing and this whole thing is very confusing to me.

(I know how to download and put soundfonts to musescore but that's about it.)

Its puzzled me for months and I've been practically pulling hair because of this lol, so thank you in advance.

Jacob B., 16