WITNESS, PLEASE RESPOND ASAP

In the summer, I was pulled over with my friend Anna and her boyfriend
Ryan. Ryan was on probation and has already served time in prison.
Ryan was driving Ann's car with a suspended license. Ann was drinking
and was breathilized and in turn got an underage. I, had a not even half of
a small drink a few hours earlier in the night, am also underage. Since I
drank such a minute amount much earlier, I blew a zero. When we got pulled
over though, Ryan ran. Neither of us said we knew who was driving the car
until they called Ann's parents. The cop had immediately asked \"where\'d
ryan go?\" before the cop had even asked who was driving. They had already
suspected it was Ryan. When they called Ann's parents because her car
is in their name, they said that Ryan was Ann's boyfriend. I was
subpeonaed to court to testify as a witness. Ryan's lawyer asked me a
bunch of questions and when he knew i was going to tell the truth, Ryan
waived all rights. I had talked to the police officer and the district
attorney before leaving and told them the truth about what happened. besides
that i had drank a minute amount. I am not subpeoned for this case as on
call witness for the higher level court since Ryan may go back to jail. My
friend Ann suggested that I plead the fifth amendment. Is this possible to
do without getting myself into any sort of trouble and does this apply to
the case?

You can yes but you should meet with counsel to discuss your own situation first, and discuss any possible charges that you may receive.