Katie can you tell us what kind of space you have and what kind of natural light you get? The right plant for my window might not be the same as yours.
Also, I suggest not growing anything you can easily buy. What are you feeding now? We can strike those off the list.
Hi Katie, have a look on Shelled Warriors shop on eBay. I grow tons of weeds for my Russian. They are like £2 and once they start sprouting they don’t stop!
I bought some shop flourecent lights for my winter indoor grow. They have two t8 5000k bulbs. You can hang them from those metal shelving units. They work good for growing indoors without anylight. I would try Amazon or eBay for your seeds.
I have a thread on here when I started growing weeds n stuff. Also check out youtube.com They have tons of stuff on growing sprouts and wheatgrass that can be applied to weeds n stuff like I did.