Daytona 1200..Hard starter

1995 Triumph Daytona 1200…Battery was knackered the other day so the AA came to my work and jump started it for me.Eventually got it going and it back fired once and was fine after that.

Prior to the battery being knackered it has seemed abit hard to start after being left out side my work for 12hrs.Could the plugs need changing,if so how many are there one the daytona and are they hard to get to ?