Tell them the truth. The immigration officer will try to find if you guys are honest or not from the conversation. Don't worry if your English is not too bad, since you marriage is true. If he/she FEELs you guys are not honest, you may get trouble.
Bring the evidence that you guys met, dated, live and other. e.g. letters, photos, untility/phone bills/drive licenses on the same address, joint bank account etc.
