No, a sole proprietorship can only have 1 EIN. However, if it is a new business and unrelated to the photography business which you mentioned, you may be able to obtain a new EIN.
There are multiple ways to retrieve your EIN if you lost your EIN.
Per the IRS website you can:
1) Find the computer-generated noticed that was issued by the IRS when you applied for your EIN.
2) If you used your EIN to open a bank account, you should contact the bank to secure your EIN.
3) Find a previously filed tax return for your existing entity since that would show your EIN.
4) Ask the the IRS by calling at 800-829-4933.
Please visit Retrieve Misplaced EIN for more information.
Additionally, Per the IRS, you will not be required to obtain a new EIN if you change the name of your business so you will still have to use the old EIN which was issued to you initially. A new EIN is usually issued when the ownership or business structure has changed.
You can also visit Do you need a New EIN? for more information.
