Ok. First let me explain that they will not expect much because you won't be able to collect much in the 5 to 7 months that you will be waiting for the interview. This is why they give a 2 year conditional Residency. At the end of the two years, you apply to remove the conditions and provide lots of evidence that you collected over those two years. For now, a few pictures, the things you mentioned, any evidence of trips together (if you haven't taken any, that's fine, but in the future), bills, statements, etc. From this point forward, you should have a folder where you put things every month.
Here is a list of things that I like to give my clients and I know that you may not have all of these things, but the more you have, the better it is.
A letter where you describe, in a very detailed fashion, the circumstances in which you met your spouse, the reasons you married, and the feelings and emotions that you have towards your spouse, and why.
If you have a child or children together, the birth certificate for each child.
Wedding pictures and pictures of other moments when you and your spouse, and other members of your families and friends have been together.
Very detailed letters from people who know you and your spouse and who are witnesses that your marriage was valid, who were at your wedding, or who knew you as a married couple.
Love letters or cards that you received from your spouse while in the relationship.
Letters from people addressed to both you and your spouse, or in which the person who wrote the letter refers to both of you as a couple.
Any types of documents that have both your names on them that show that you bought a car, a house, furniture, or anything else together.
Any rental or lease agreements for your home or apartment with both of your names on it or a letter from the building manager or owner proving that you lived together.
Bank or financial statements that show that you had or have a savings or checking account together.
Any insurance documents that show that you were or still are covered by your spouse's insurance plan, or that your plan covers or covered him or her.
Bills, such as electricity, water, heat, cable TV, phone, or others that show both you and your spouse's names.
Jointly-filed Income tax papers (both your names).
An identification card that shows that shows a common address.
Membership cards for video clubs, grocery stores or similar businesses, that show joint membership.
Any other documents that prove your relationship.
Please let me know if you have any additional questions as I will be happy to respond, but because this case is the type of case that I love to handle, I will now send you a low-cost offer so that I can pass on my personal phone number and email. I cannot discuss pricing on an open forum, but if you accept, you will see I have multiple services available to you from document review to full representation and all at very reasonable prices. You won't be disappointed as these are my favorite cases to do and have been doing them for many years. If you decline, no problem, you can ask additional questions without any additional charge. But PLEASE remember to leave a positive rating for me. You can do that by clicking on the 3rd, 4th or 5th stars if you see them, or the smiley faces if you see them. Also, a bonus is always appreciated if you feel I earned it. And finally, your question does NOT close just because you leave a positive rating. I can still answer additional questions for you without additional charge. Thank you for your understanding.