Answer by taking a quote from the following article:

D'Angelo was born Michael Eugene Archer, in Richmond, Virginia on February 11, 1974, to a Pentecostal preacher father. He was raised in an entirely Pentecostal family. Archer's musical talents were discovered very early on. At 3, he was spotted by his 10-year-old brother Luther, playing the house piano.

D'Angelo signed a publishing deal with EMI Music in 1991 after catching the attention of record executives through a demo tape, which was originally by the group. After an impressive audition for EMI execs, a three-hour impromptu piano recital, D'Angelo was signed to a recording contract in 1993. A&R-man Gary Harris was primarily responsible for his signing, while manager Kedar Massenburg helped negotiate the contract as well. Massenburg became D'Angelo's manager after hearing of him through "the buzz on the streets". He had previously managed hip hop group Stetsasonic and formed the artist management-firm Kedar Entertainment in 1991, which he diversified into production, music publishing and publicity.  In 1994, his first significant success came in the form of the hit single "U Will Know". D'Angelo co-wrote and co-produced the song for the all-male R&B supergroup Black Men United, which featured R&B singers such as Brian McKnight, Usher, R. Kelly, Boyz II Men, Raphael Saadiq and Gerald Levert. D'Angelo composed the music for "U Will Know", while his brother, Luther Archer, wrote the lyrics. Originally featured on the soundtrack to the film Jason's Lyric (1994), the single peaked at number 5 on the Hot R&B/Hip-Hop Singles & Tracks and at number 28 on the Billboard Hot 100. The music video for "U Will Know" featured D'Angelo as the group's choir director; he reprised the role for the live performance of the song at the Soul Train Music Awards. That same year, he wrote and produced the song "Overjoyed" for the Boys Choir of Harlem, which appeared on their studio album The Sound of Hope (1994). The success of "U Will Know" helped build the buzz surrounding D'Angelo, which was followed by a number of highly promoted showcases, and added to the buzz among music industry insiders.  Brown Sugar was released in June 1995. Although sales were sluggish at first, the album was eventually a hit. The album debuted at number six on the US Billboard Top R&B Albums chart in the week of July 22, 1995. It ultimately peaked at number four in the week of February 24, 1996, and spent a total of 54 weeks on the chart. Brown Sugar also spent 65 weeks on the Billboard 200 and peaked at number 22 on the chart. It sold 300,000 copies within its two months of release. The album had been selling 35,000 to 40,000 copies a week through to November 1995, and by January 1996, it had sold 400,000 copies. With the help of its four singles, including the gold-selling Billboard Hot 100 hit "Lady" and R&B top-ten singles "Brown Sugar" and "Cruisin", the album reached sales of 500,000 copies in the United States by October 1995. On February 7, 1996, it was certified platinum by the Recording Industry Association of America, following shipments in excess of one million copies in the U.S. The album was certified gold in Canada on May 9, 2000. Its total sales have been estimated within the range of 1.5 million to over two million copies.

What was his first single?
In 1994, his first significant success came in the form of the hit single "U Will Know".