If being late for work was not an habitual problem, you should not have any difficulty getting unemployment benefits. But if you were repeatedly late and received warnings that if it continued, you would be terminated, the employer could claim you were fired for misconduct and fight your claim for benefits. There are not enough facts to address why the employer says you were fired for stealing, but the real issue is whether your termination was for misconduct.
You could appeal the initial decision to deny your benefits, within 20 days of the notice you received, and ask for a hearing. At the hearing, you can present your side of the story and any evidence to support your case to an administrative law judge, who will determine whether your dismissal falls within the definition of misconduct. In order to prepare for the hearing, ask the appeals office for a copy of any documents the employer has provided to EDD supporting its contentions.
I concur with Mr. Kirschbaum. In preparation for your hearing, you may also wish to read the information on employee misconduct provided by the Employment Development Department: http://www.edd.ca.gov/UIBDG/Misconduct_-_Table_of_Contents.htm.