Hallo! I have published two phrasebooks in kindle (amazon) as ebooks where you can learn basic Icelandic. I have this easy to read phrase book in Icelandic and English, and Icelandic and German (Deutsch). You can read up on it before your trip to Icelandic so you can communicate. They are called Læra Islensku - Let´s Learn Icelandic and Læra Islensku - Lernen Islandisch! If you do not have a kindle fire, you can simply download kindle as an app on your android for example. I think it is free if you have kindle unlimited. I hope you can check them out! Thanks / danke / takk fyrir :)
Ps. I can also provide Icelandic lesson via skype, just send me a message. Similarly for walking tours or any tour for special request you can message me and I will create a tailor made tour as per your preference.