Firstly, introduce yourself as their Sponsor. Welcome your PSA to SFI and your team.
I suggest asking them what understanding of SFI they have. This will let you know if you need to explain to them about SFI, it also gives you an idea how much guidance to start them with and if they will need a little extra of your time. Be positive and encouraging, let them know you will work together with them as they learn and build with SFI and you're here to guide and help.