How much prodigy had concerts in 1990 year?
I know for two. More?

Had 5 dates:
1990.02.?? - The Labyrinth Club
1990.03.?? - The Raindance
1990.04.?? - The Labyrinth Club
1990.??.?? - ??????????
1990.??.?? - Hatfield College

i believe it was a nice show.

a little more details
??.02.1990 - The Labyrinth, London, England
??.03.1990 - Raindance, England
??.04.1990 - The Labyrinth, London, England
??.??.1990 - Hatfield College, Durham, England

"With this line-up, the Prodigy started to do what few dance acts before them had done - they gigged. Bands like N-JOI and Shades of Rhythm had built up a large fan base long before the Prodigy's arrival, but it was the sheer weight of hard work that saw Howlett's band leapfrog all of their peers within a matter of a few months. Their early shows were sometimes ill-attended, like their fifth gig at Hatfield College where there were only nine people in the crowd, including five staff. Conversely, their twelfth gig was at Raindance, a massive rave attended by 12,000 people."
Martin Roach

But is this right? Acording to the book Liam was still just Dj-ing in the summer of 1990 and keith still problably traveling around europe.... I thougt the band started around fall 1990 in sep or oct ?

That seems about right.

The club was called the 4 Aces. The night was Labyrinth.

it was 4 Aces before the rave times, i mean it was a reggae club 4 Aces, and a friend of the prodigy Ziggy had relations in reggae public, that's why he organized so fast the first show there, after that, the club was renamed to Labyrinth.