Hi everyone I think I signed up to the forum some years back and forgot about it (wasn't serious about losing weight probably). But here I am again and I really need to lose around 15kg to be back to a normal weight.
I have to idea how and where to start and I hope to be inspired with all you who have had a successful weight loss journey.

If you have enough inspirations, then watch out for what you eat, or in other words, "dieting", "fasting"...etc XD Research about them. Plus if you have time then do physical exercises, 30 minutes a day, 3 days / week would be just enough.
If you really want to drop weight fast and don't care about researching diet at all, use supplements.

awesome way to start

Oh boy...please do not resort to fad diets or supplements. You might lose weight, at the expense of your health, but you also are EXTREMELY likely to put the weight back on.

The best thing you can do is look for ways to permanently change your lifestyle in small ways and commit to a long term change. You can make relatively small changes and get there if you are willing to have patience. For example, just cutting out soda (or cutting the number of sodas you drink in half), to start with. For me, I don't drink much soda to start with, I had to cut out fruit juice (huge sugars) and cut back on the HUGE quantity of milk I was drinking. I went from 3 gallons of milk a week to about 1 now. I'm working on cutting it back further, little by little.

Also start walking or swimming, or biking, whichever you like best that is easiest for you, just get moving most days of the week. Integrate some kind of strength training at some point for the best result, but if that sounds too overwhelming to start with, don't do it for now. Swimming or biking have a strength element to them, too. But even just squats, lunges, planks, etc that you can do in your own living room, with no equipment, is great to start. Youtube is a great resource for suggestions.

And then try to make healthier, mindful choices. I tell myself before I have a snack, I have to stop and ask myself whether I really am hungry, or whether I'm actually bored. If I'm bored, I go for a walk instead, or read a book, or do some jumping jacks, or do the dishes, or anything that isn't eating. Sometimes, I just come and check 3fatchicks for new posts, which gets my mind back off the snacks I wasn't really hungry for anyway. But if I really do want a cookie, or whatever, I find that I am better off to just go ahead and have 1. ONE being the key. If I try to deny myself completely, I just end up trying to satisfy the craving some other way, and usually eat more calories than the cookie would have been in the first place.

Ultimately, I've gradually cut most of the added sugars out. I still have a bit of chocolate every day, but I'm going to try next to transition to dark chocolate, which is healthier. We'll see how that goes. I really feel a lot healthier with less sugar in my diet. But I didn't do that all the first day, it's been a gradual transition.

But you do you. Find one unhealthy food/drink you are willing to cut back on, and do that for a while. Then choose another one. Move more. Don't snack mindlessly.

Those tips will go a long way. So far, I'm down 60 pounds in about 9 months. Sure, some are faster, but I'm still losing about a pound a week, and I feel like I could eat this way forever.