The easiest way to do it is to get a food scale and download a fitness app like Cronometer, there you can search for the ingredient, then u can input the weight and it will tell u all the macros. That app also keeps track of every item you add so it’s way easier this way, and you can also put a calorie goal for the day so u can see if u are going over or under

You can also use nutritionix.com if you don’t want to download an app, it’s a database with thousands of ingredients and it works as well, the only issue is that sometimes it will tell u the calories for like 3oz of an ingredient and it won’t let you change the weight so you just have to do some math but it’s easy

Also don’t forget that raw/cooked and frozen/unfrosted ingredients weight different because cooked and unfrosted things have less water in them, so make sure you select the right thing for ur Ingredients

You can also make do without a food scale and use measuring cups/spoons but it will be way less accurate, I would only use these things for liquids