Good evening Inbar and welcome back!
Thank you for reaching out to us.
I would love to help you with this topic.
That’s a great question.
I am assuming you are talking about the Community Events form.
The short answer is yes, you can achieve what you are looking for.
To do that will require some template customization.
You might want to read our Themer’s guide to get a sense of how that works.
You could then add a validation for each field to set the length of your choice.
This can be accomplished in many ways: JQuery, JavaScript, etc..
Most people find using the following method to be the simplest: http://www.w3schools.com/tags/att_input_maxlength.asp
Let me know if that helps.
Have a great day!
Geoff B.