Ruling on delaying marriage because of studies for one who fears that he may do something haraam
Question

I was born and raised a Christian, however since learning about Islam I have recently converted. Before my conversion I allowed a fallen Muslim to touch me. Since then I have not allowed for any touching, inappropriate words, or unsupervised visits. I have repented and so has he of these terrible acts. His parents are helping me to understand and follow the Quran. He has asked me to marry him, and I wish to do so. The problem is this: his parents wish for him to wait to marry until after college. Should I wait to be engaged or should I become engaged immediately?  I know that it is better to marry than to commit immoral sexual acts, and I am afraid that these acts will be very tempting, especially in our minds, even if we do not see each other alone (which I do not wish to do). I want to respect and love his family, and I do not know how to appropriately arrange for such things as marriage when they are the only Muslims I know. PLEASE HELP! I want to enter into a moral arrangement and I do not want to be a girlfriend!
Praise be to Allah.Who has guided you to Islam, and has bestowed this great blessing upon you. We ask Him to keep you steadfast. One of the blessings that Allaah has bestowed upon you is that Islam wipes out whatever sins came before it, and we ask Him to accept your repentance and the repentance of everyone who repents. 
With regard to engagement and marriage, our advice to you and to this young man is to hasten to get married if possible, especially since you are afraid of doing something haraam. In this case, the issue of marriage takes priority over the issue of studying. So long as marriage is what you both want, you should try hard to convince his parents of that. Remind them of what the Prophet (peace and blessings of Allaah be upon him) said to the young men: “O young men, whoever among you can afford to get married, let him do so, for it is more effective in lowering the gaze and in guarding one’s chastity. Whoever cannot afford that, then he should fast, for that will be a shield for him.” Narrated by al-Bukhaari, 5065; Muslim, 1400.  
He can also remind them of how many temptations there are, and that the Muslim has to resist them by every legitimate shar’i means available. Undoubtedly marriage is one of the greatest means of protecting oneself against these temptations. Indeed, the scholars state that marriage is obligatory in such cases. (al-Mughni, 9/341). It may be sufficient to do the marriage contract which meets the conditions stipulated in sharee’ah, until you are able to do the waleemah (wedding feast) and consummate the marriage, because this will make it permissible for him to be alone with you and to touch you, because in this case he will be considered to be your husband according to sharee’ah. If you can do that, this is good. But if his family insist on refusing, and this young man is afraid of doing something haraam, then he must try hard to get married if he is able to, even if his parents do not give him permission, whilst also trying to please his family as much as he can. If he is unable to do that, then either you have to be patient and follow the advice of the Prophet (peace and blessings of Allaah be upon him) to those who were not able to get married, which is to fast, and try to keep away from places of temptation and situations in which desire may be provoked, until Allaah brings you together in a good way, or your legal guardian (wali) has to try to look for another righteous person for you to marry, so that you will be safe from the risk of doing something haraam. 
It should be noted here that if you become engaged according to sharee’ah, that does not mean that he is allowed to sit with you or to touch you or to go out with you or to speak to you unnecessarily, until the marriage contract is done between you, fulfilling all the conditions stipulated in sharee’ah. 
For more information on these conditions see Question no. 2127, 7193. And Allaah knows best. 
We ask Allaah to make it easy for you to do the right thing and to ward off evil and immorality from you. Ameen.