Hell yeah it's big enough! Also, since it's the end of summer, see what you can do to pick up parts to build yourself a mash tun.
I am not the most mechanically inclined human on these forums, but I can do simple stuff like oh... brew beer, knit a scarf, put together Ikea furniture, do basic home repairs, and I built a mash tun!
BIAB is a GREAT place to start, but lifting a bag of heavy wet grains and waiting for the drip drip drip gets old. You could probably pick up a 10 gallon water cooler on sale at your local home improvement store, and the hardware isn't too hard to come by either.
Really... it's a lot easier than it seems and will make your AG experience seem SO much easier!