im also pretty new to fighting games.
but from what i heared, playing arcade mode is verry diffrent from playing against other players.

especially in older games hi level cpus tend to fight dirty,
using input reading and op boss characters.

input reading cpus basicly have inhuman reflexes,
and will counter big comittal attacks like jumpins or tatsu as long as they are free to move.

so throw out non-commital pokes, untill they do something you can counter.

if its the bosses you are struggeling against,
only perseverance will help. (unless you find a move the ai cant deal with)
they are designed to take your quarters.