Hi and welcome to AudioJungle!
Please have a look at my suggestions as I think they could fit your ad well:
Best wishes and good luck for your project 
- Sold between 100 000 and 250 000 dollars
- Author was Featured
- Item was Featured
- Exclusive Author
- Repeatedly Helped protect Envato Marketplaces against copyright violations
- Author had a File in an Envato Bundle
- Europe
- Has been a member for 3-4 years
Hi man! Please, listen this track:
- Author had a File in an Envato Bundle
- Author had a Free File of the Month
- Author was Featured
- Bought between 10 and 49 items
- Europe
- Exclusive Author
- Has been a member for 4-5 years
- Item was Featured
- Attended a Community Meetup
- Author had a File in an Envato Bundle
- Beta Tester
- Bought between 1 and 9 items
- Exclusive Author
- Has been a member for 2-3 years
- Interviewed on the Envato Notes blog
- Microlancer Beta Tester
- Referred between 10 and 49 users
Hi mianmars,
I think I might have a winner for you. This track is quite popular when it comes to all things kids! It is non-intrusive, happy and catchy, which I feel are all very important for the feel of your project and the message you are delivering.
http://audiojungle.net/item/childrens-storytime/135235Best of luck and welcome to AudioJungle!! 
Cheers, OhmLab
Here are a couple of ideas for you:
http://audiojungle.net/item/redeeming-season/351460 http://audiojungle.net/item/the-moment/350258 http://audiojungle.net/item/little-hearts-piano/400356 http://audiojungle.net/item/puppy-love/398559Good Luck With Your Project !
Cheers!
Wesley
Hey, man! I am also a novice on the site. Try OST .http://audiojungle.net/item/dancing-dolls/511210 Yours sincerely kashick.
Hi,
Try this one:
http://audiojungle.net/item/mountain-breeze/308738
The track has few different sections that can be cut and combined to match ad’s pace.
If you need it edited I can help you with that.
Cheers, M
