A month in is the perfect time to start giving nutes (assuming you're in soil). Go check out your local hydro shop if you've got one and look for something with a ratio around 20-10-10 (20% Nitrogen, 10% Phosphorus, 10% Potassium) for the veg state. For flowering state, you'll want something more like 10-20-10. Start off on 1/4 strength so you don't burn your plants and you can work your way up slowly.
Look for something that includes secondary nutrients and micronutes if possible. I don't know as much about those, but I know that a little bit of them is necessary. Also, avoid slow release fertilizers.
