Hi and welcome!
IMO is "in my opinion" sometimes seen as IMHO which is "in my honest opinion" or "in my humble opinion".
ROFLMAO is "rolling on floor laughing my arse off" and ROFL is "rolling on floor laughing" and
ROFLMBO is "rolling on floor laughing my butt off".
Asking questions is a sign of curiosity and intelligence!! Ask away!
Nice to meet you!
ttyl (talk to ya later!)