All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
First of all, we congratulate you for the blessing of being guided to the truth and for abandoning the way of misguidance. So, you should praise Allaah as much as possible for this and be keen on acquiring beneficial knowledge, performing good deeds and keeping company with righteous people.
For more benefit on the Ismailite sect and the ruling on being affiliated to it, please refer to Fatwa 82794.
As regards marriage, it has specific pillars and conditions, and if they are met, it is a valid marriage. The most important of these conditions are the consent of the guardian and the presence of two witnesses; for more benefit, please refer to Fatwa 83629.
However, if you wish to marry a specific girl and it becomes clear to you that she is a religious girl, then first of all, you should seek the help of Allaah to enable you to marry her, then endeavour to convince her guardian and ask some righteous people to intercede for you with him as Allaah may enable you to marry her. However, you should know that being steadfast on the right path and having a good moral conduct are the most important factors for being accepted as a husband.
As regards love before marriage, then this matter is already discussed in Fatwa 120630; so please refer to it.
Allaah Knows best.