Will I do federal time for an unlawful possession of a firearm in the state of Texas but my record is clean

If you were charged under TX law, Unlawful  carry of a firearm is a class A misdemeanor. The punishment range is up to 1 yr in county jail, and a fine up to $4k. You may have legal or factual defenses; and, you may be able to do probation, not jail time. In some instances, we even get these dismissed after the person completes conditions - just keep in mind that every case is different, and many factors will come into play. Under Federal law there are firearm offenses as well, but most often are prosecuted where there is an illegal weapon (full auto, sawed off shotgun, etc), or the person is a convicted felon with a firearm. "not reading your rights." - this only matters if you are questioned after being taken into custody. Your miranda rights attach when you are arrested and intereogated. If they don't question you after arrest, it really makes no difference. Hire a lawyer you trust for the best outcome. You can't choose your appointed attorney, but if you cannot afford to hire someone, make sure to follow up with appointed counsel frequently.