The phrase "attempting to enter a" is correct and usable in written English.
It can be used when describing an effort or action to gain access to something, such as a location or system.
Example: "The security footage showed a figure attempting to enter a restricted area late at night."
Alternatives: "trying to access a" or "seeking to enter a".
I also ran across a "schiava moresca battezata" (baptized Moorish slave) attempting to enter a convent in Parma as a conversa.
In Belfast, the police were attacked with flaming gasoline bottles by a mob of Protestants attempting to enter a Catholic neighborhood.
A change made for iOS 10 means that you cannot move past the lockscreen without activating the home button, even if you are attempting to enter a pin code to unlock the device.
In February 2009 Antonio Margarito had his licence to box in California revoked for one year after attempting to enter a ring to fight Shane Mosley with his gloves loaded with a "foreign substance, jeopardising the health and safety of a fellow combatant".
With the prospect of McDowall being sent on gardening leave, as is the case with his predecessor Ally McCoist, former England player Stan Collymore asks if Rangers are "attempting to enter a team into the Chelsea Flower Show".
A British-Iranian law graduate, Ghoncheh Ghavami, was recently released from prison in Tehran pending trial for attempting to enter a stadium to watch a men's volleyball match.
The bomber had attempted to enter a nearby hotel but was refused entry.
A man was shot and wounded after he attempted to enter a house in Gig Harbor, Wash., Thursday afternoon.
At the beginning of the weekend, some Denver activists attempted to enter a conservative bloggers' convention called BlogCon on Friday, the Post also reported.
The men were among six people killed after two gunmen attempted to enter a house in the suburb of Nazimabad where up to 90 women were holding a majlis, a traditional gathering in Shia Islam.
Christenberry first became fascinated with the Klan in 1960, when, out of curiosity, he attempted to enter a KKK rally in Tuscaloosa courthouse only to come face to face with a lone hooded figure guarding the entrance.
