Boys of this age group have grown a lot but are not mature enough. They are full of ideals. Is your colleague a hardworking and motivated person? If so, it would be good to give him an inspirational bestseller. It can also reflect the cultivation and taste of your female colleague.
1 At the age of 24, he should still be more playful. You can ask him for a photo of his life (of course, it means that there is no other meaning) and give him a real doll that can be bought online. It is fun and commemorative.
2 You colleagues should discuss who will buy the cake. If you really don’t have time to prepare or don’t know what to buy, just volunteer to buy the cake.
3 Do you eat at a restaurant or at his house? If you eat at his house, buy the dishes and ingredients in advance, cook a dish that you are good at, and say a few nice words during the meal, and send blessings from the heart, such as good work and finding your own happiness. Sometimes sincerity is more important than anything else.