I've seen this question asked a few times in recent days. Please allow me to answer it so you don't have to wonder any longer.
The NFL just issued a press release announcing when training camp opens for each team. There are typically two reporting dates--one for rookies and one for veterans. The first "official" day of training camp, according to the NFL, is generally held the day after veterans report.
What does that mean for your Houston Texans? It means rookies report to the Methodist Training Center adjacent to NRG Stadium on Monday, July 25th; veterans report on Saturday, July 30th; and the first "official" day of training camp is Sunday, July 31st (which just so happens to be the first practice open to the public).
We're so close, people. Football is almost back.