Do I have to give a 30-day notice if I do not plan on getting my security deposit back? What will happen if I don't give 30 days and its in my contract?

If you don't give a 30 day notice the LL can and will likely keep your security. However, if there is any damage to the unit the LL can still comes after you for repairs and cleaning. It is adviseable to give the notice.

If you do not give a 30-day notice, you are breaking the terms of the lease.

Most likely what will happen, is your deposit will be kept, if there is any damage you will be charges additionally, and you will be responsible for the amount of rent due until the end of the lease.