I have the first hut built, but my villagers still cannot give birth after so many tries. The population still stuck @ 7. I thought after the 1st hut is built you can have 15 people...

Do you have at least 400 food? Your villagers will have no interest in breeding until you have that much stockpiled -- they might go indoors, but more likely that they'll tell you they're not interested because they're hungry.

It will also take a while because (I'm guessing) you have Level 1 Fertility. It might take 15 or 20 tries to have a successful mating at that tech level.

To save yourself time, pick the female you wish to have a baby, and set her preferred skill to breed. Once she's a Trainee Parent, she will keep trying even if you have the game off.

They kept going indoors and coming out with nothing. And they did not have any feelings. I have 383 food. Is that enough? I have 2 children and 5 adults, all the girls and boys are not having any babies

If they are going inside, then they are happy to try -- but it's not a big chance that they'll have a baby even if they do go inside. It might take more than 20 trips to the hut (they go indoors even if they are not successful making a baby).

If you really want to speed this up, you can interrupt them -- they do not need to go indoors for the breeding to be successful. Just pick up the female and drop her on the male again to repeat the try -- if your population increases when they kiss, you have a baby. If not, pick up and try again.

383 is apparently enough food if they are trying to breed on their own -- 400 is a rough estimate.