Hi! Yesterday I decided to prepare our raised veggie patch and plant some seedlings. (haven't planted in a while because of Australian hot weather). I have absolutely no experience with gardens. We went to a garden centre and got 25L of organic composted chicken manure, 25L of organic mushroom compost, 25L of organic compost, and 3 x 25L of organic soil. We turned all of it into the existing soil and planted everything immediately. Our bed is about 4 square meters. This morning I noticed 2 of the seedlings have died and my father in law said I've made a mistake and everything will die because I added to much manure and compost! I'm so devastated and am note sure what I need to do to fix this. Should I take all of the seedlings out and add more soil? You're advised would be sooo appreciated. Thank you in advance.
He is, absolutely, correct. You will want to use the manure and compst somewhat sparingly. You will need to restart after you add more potting soil, or topsoil. You may also want to add dolomitic lime to correct the pH, and balance out some of the acidity of the manure.
This article will give you information on building the proper soil: https://www.gardeningknowhow.com/special/organic/the-importance-of-soil-for-an-organic-garden.htm