You can google 'tomatillo companion planting' to read what a few sites say about it. Probably will not find a university source that find it reliable for bug control. Here looks like a pretty nice overall garden guide
If you are new to gardening, I recommend NOT worrying about 'mastering secrets of companion planting'. More important to get plants/seeds in the ground and start learning and growing.
My tomatillos sprawl, root if they lay, and do not keep stinkbugs off my tomatoes, nor all the bugs off any brassicas.
What else would you like to grow besides tomatillos?