The relationship between Texas landlords and their tenants is governed by several statutes, particularly Chapter 92 of the Texas Property Code, and by various court rulings. However, the most important source of information about your relationship with your landlord is your rental agreement, whether it is written or oral.
Some landlords prefer oral agreements, but it is more common for them to require your signature on a written lease. Be sure to read the lease carefully before you sign it.
If you want to change a part of the lease, discuss it with the landlord. If the landlord agrees, the two of you should decide how you want to word the change, and then write it into the agreement. Both you and the landlord should then initial the change. For example, many standard leases prohibit pets, but your landlord may be willing to accept a pet if you put down extra money as security.