I have been separated from my ex husband for almost a year. Islamic divorce was recited less than three months ago, but I have met someone who I want to marry. out of my ignorance I have not taken the best route, and we have had relations. if I repent to Allah and seek forgiveness is it possible for me to marry him in the future?

If the relation was with marriage contract, then there is no way for you to get married with him again.
However, if the relation was made without marriage contract (zina), you both can refer to Sheikh Mohammad Ishaq Fayyadh, in this particular issue, and get married after completing the iddah.