If anybody could give me a few tips as first time ...

After you’ve planted your seeds or rooted your clones, it’s time to get them growing. Lower your reflector so that it’s closer to the plants rather than making them stretch to reach for light. Raise the lighting system as your plants grow. Set your light timer to be on for 18 hours per day and off for 6 hours. During this vegetative stage, the plant will grow leaves and branches but no flowers (unless it’s an auto-flowering plant). Avoid overfeeding and overwatering your plants at all costs. Err on the side of caution as it’s always easier to add more nutrients or water than it is to take them away. Marijuana roots prefer a wet/dry cycle so lift up your buckets and you’ll get a better idea for if they need watering or not by the weight. The first sign of overfed plants is burnt leaf tips. The first rule of how to grow weed is to learn to stay off of its way sometimes. Don't worry about nutrients in the first 3-4 weeks unless your plant shows sign of deficiencies. I'm also growing stardawg by fastbuds if you want to check out my diary for comparison. Good luck