What can I do if I texted and called my landlord to fix windows and n unsecure front door but he has failed to answer me back?

In every lease there is an implied warranty of habitability which requires the landlord to maintain the premises in a habitable condition by complying with local and state housing codes.  When there is a breach of the implied warranty of habitability, the tenant notifies the landlord as you have done and the landlord is required to respond within a reasonable time by making the necessary repairs. 

The unsecure door is a safety issue which may constitute a housing code violation and breach of the implied warranty of habitability.  Depending on what the problem is with the windows, that may or may not rise to the level of a housing code violation and breach of the implied warranty of habitability.

When there is a breach of the implied warranty of habitability, the tenant can make the repairs (have someone repair the unsecure door) and deduct the cost from the rent.  This would probably be your best option.  However, there are other remedies for breach of the implied warranty of habitability such as moving out and terminating the obligation to pay rent for the balance of the term of the lease or staying on the premises and withholding rent and defending against eviction.  You could also contact the local housing code inspector to bring an enforcement action against the landlord for housing code violations.   Not all maintenance problems will constitute a breach of the implied warranty of habitability.  Your best course of action would be to hire someone to secure the door and deduct the cost from the rent.