Side Gig Without Income

I am a W-2 employee but have a side gig related to real estate investment. I do not have a LLC or DBA. Last year I incurred related expenses such as marketing costs, mail box rental, mileage, and professional membership fees. Can I deduct any of these expenses without related income this year? Someone told me to keep tracking the expenses and carry them into the next year when I do make money from this. Are there any other options to handle these expenses?