New and need support

Without knowing your stats, goal, chosen weight loss rate and calorie goal, some general advice:
- if you chose a fast rate of loss, you might consider choosing a slower rate of loss, which will give you more calories to consume. Even if it's just temporarily, to let your body get used to a lower calorie intake
- satiation is very individual. Some things you can try is to increase your protein intake and fiber intake. It's also worth experimenting worth meal timing. Some people do well with fewer, larger meals-others prefer smaller more frequent meals throughout the day.
- being more active is also a way you can increase your allowed calories

Lietchi gave you good advice above.

It's OK if it takes a while to figure out what keeps you full. It's also OK if you go over your calorie goal a bit while you're figuring it out.

The major plus of a calorie counting method is that - if you put in the work - you can figure out how to lose weight and later maintain your healthy goal weight, eating foods you personally enjoy, find practical and affordable to buy/cook. You can make your eating an easy-to-sustain habit, not some weird fad diet, or buying expensive diet foods or whatever. You're trying to figure out a happy eating pattern you can follow long term, not punishing yourself for past weight gain, y'know?

When you do that, the first bit will be a learning process, and learning processes involve some failures and adjustments. Don't freak out about that, it's just how it works.

I get that you're over your calorie goal today. Switching to a slower loss rate as Lietchi suggests may help with that. What I wouldn't suggest you do is starve for the rest of the day. I'd suggest you think of something to eat that you may find pretty filling, that's not super high in calories.

Most people are going to find one of the following filling: Protein, fats, or high-volume/low-cal foods. For today, I'd suggest you consider eating some calorie-efficient protein (maybe chicken or tuna if you have some available?) and/or some non-starchy veggies (like cucumbers, tomatoes, broccoli, cauliflower, or that sort of thing, if you have some - frozen is fine). See if one of those things help you feel more full.

A specific food many people find filling is a whole baked potato, just regular white potato. They're surprisingly calorie-efficient and nutritious - it's the fatty toppings we usually use that make them truly high calorie. If you need something on it, consider something like Greek yogurt or cottage cheese if you have some of that, or just slicing it and using some seasoned salt. That may not be gourmet eating, but it might be filling.

A second food some people find filling is oatmeal/porridge. Again, what you put on it matters. Some Greek yogurt or fruit would be good options, if you have some.

You might even find that something like hot herbal tea or hot broth helps you feel full, with hardly any calories at all: Worth a try!

The point is, you haven't lost the battle if you end up a little over calories today. Don't try to white-knuckle it through (and maybe have some hunger consequences again tomorrow). Instead, try to eat something moderate calorie, and start working on figuring out what you personally find tasty and filling. It will be fine. You can do this!

Wishing you much success!