Will I gain weight immediately if I ate 3000 calories today?

Technically, yes. You've had a big intake of salt so your body will be clinging onto that giving you a bigger temporary mass with water weight. Salt makes your body retain water, making you look bloated. You've also got a lot of food sitting in your gut likely having difficulty being digested, so you'll be bloated and heavier.

The carbs from the noodles, bread and chicken batter and sugar from cake, white bread and drinks break down into glucose. Glucose is important to fuel your body but a higher intake of it will make you gain weight. When you've got more glucose fuel in your body than you actually require, it'll be stored as fat.

The amount you've had will not damage you or make you gain weight from one sitting, however there is an addictive quality with sugars. Eating a lot of sugars will end up making your body eventually store it as fat. A lot of people overlook this. Eating a lot of sugary foods because they're "fat free" however these foods make you gain weight just as much.

Long story short, if you keep up the binge eating you will gain weight, fast. If you eat 3000 calories and do not put in the work to burn off 3000 calories (which is near impossible anyway) you will gain weight. Try macro counting apps if you are curious about how many calories your body should be having a day for your age/gender/height/exercise routine.

That's not healthy I doubt you'll gain weight. If you make it a habit yes you will!
So you should burn that extra calories by walking.

dude you are actually underweight!!! (calculated the bmi according to your country) underweight is not so healthy too!
u should actually gain some weight! but the food u ate is a little bit junky..... but since its just only today its ok............... but u really need to put on some weight by eating healthy food!

I really hope that Zeppie can weigh in because I think she'd probably knows a lot more than I do.

Still, you have to remember that Calories is nothing but a unit of measure for energy. A given volume of gasoline has a Calorie count, as does a mass of firewood. All it means for the human body is how much energy a given mass of food contains and can be released when burned or otherwise broken down.

Your body uses the energy to make ATP which is delivered to the mightocondria to create the energy to keep the cells alive. Excess is then converted and stored as fat, but this is a long term process because fat is nothing but energy storage.

So, short answer, no, you won't immediately gain weight. Don't worry about 3000 Calories here and there, worry about what that does to your average daily Calorie intake and the amount of exercise you need to do to keep intake and usage balanced.

Also if you don't regularly exercise, you should consider starting. I do ranch work to balance everything, but some people go to gyms, others do sports, others jog, it's up to you

Not immediately, no, but Its not something you'll want to make a habit of unless you need that many calories.

Nigga I eat like 4000 and I'm a'ight.