>all Muslims should be Sufi
You can't "be" Sufi. You can be Muslim. You can be Sunni, or Shi'a, or Ibadi; but you can't be Sufi. You can embrace Sufism and study in the Sufi way, but you can't "be Sufi".
>interested in practising Islam
If that were true, then you would practice Islam. Your worthiness for this board is that you either are Muslim or you are interested in becoming Muslim. If you're not Muslim and you're coming here talking about Irfan and "the mystics", then we can spot you a mile away and will know you're not sincere. If you sincerely wish to study Islam, then start with Qur'an. Read it, then read it again, then again, then read it again, then go to a mosque (hint: there are no "Sufi mosques") and learn how to pray, then read Qur'an again, and one more time, then start reading the Sunnah of the Prophet, and so on and so on and so on for 10 years or so, living every day as a Muslim and in the way of the Prophet … THEN you can start the basics of Irfan.
Rumi grew up Hanafi (Sunni), was taught Islam well into adulthood, before he started looking into Irfan. Were he alive today, he'd tell you the same thing: you can't just "be" Sufi.