What is the IMEI2 on my iPhone SE?

Also I'm trying to use my WiFi calling feature on my iPhone SE(2nd gen) to make important calls til I can get another monthly data plan thru my Straight talk carrier and said I needed to contact Verizon to do this?? But also says I have to have my TFW sim/carrier service activated? Can I get my WiFi calling actived in any type of way? I tested my phone and was told my phone was WiFi calling capable and LTE capable, then got lost, lol can you plz help me with this bro?

Oh okay and thanks! So if I'm using TFW carrier service thru straight talk, can I still have it activated with the different carrier "Verizon" ? And you can see from my screen shot earlier that I have a NAI service....my#.....then...@vzims.com ?? Which means it is a Verizon carrier service,.., correct??