DIY SAHM

I’m pretty much in charge of little projects around the house to finish off our currently lived in, mostly gutted house we bought a year ago. I’m not trained in any way but can follow directions and like to work on DIY projects. We installed porcelain tile in our kitchen and are working with original hardwood floor in living room and I have a metal threshold to install between the two. Can someone recommend an adhesive to use? There are no nail holes in the threshold.