How heavy? Deadlifts and Squat.

there is no hurting ur self if u go higher and higher in weight, cuz ur body get used to the weight/ only danger is if its too heavy to handle and/or bad form

Go as heavy as you feel comfortable with. If you're unsure about your form, use lighter weight that you know you can handle until you've got it down perfectly. If you're still really worried about injuring yourself, don't do either exercises.

I just started doing deadlifts and squats. I started with 30 Kg for each.
I do it once a week, 5x5 for deads and 3x10 for squats.

My question is, how much weight should i add per week? I was thinking 4Kg for Deads and 3 for Squats.

Its considered polite to make your own thread to ask questions. asking outright questions in other peoples threads is considered hi-jacking. but as you have done it already, its to late how much weight you add is down to you. I don't know how hard you are finding your current weight or if your form is correct and established enough for you to go heavier. If you know your form is very good and embedded into your system and you would be aware if you become sloppy then you could add enough weight to leave the last rep of your sets as just do-able. so you see its almost impossible for anyone to say for sure. if you are unsure of your form, I recommend you do a short video(front and side view) of you doing them. and ask advice as to if it looks correct. or better still have someone that knows what to look for spot and watch you. then they can help with the correct weight choice. if you are certain of you form and abilitys but just need to get stronger then yes a good start would be a few kg at a time. this way you will build muscle strength slowly and keep your form.

Start off very slow, learning proper form, sacrifice gains the first couple of weeks for form. Then once you start increasing the weights, take them seriously, concentrate, and never go to failure.

Those simply rules will keep you safe. Those getting injuries use bad form, go to failure, or just don't concentrate. Sure some get hurt by no fault of their own, but that's a small group.