gear ratio

I bought a 1978 Honda Hawk T2 about two years ago. It was in perfect condition. It's 400cc, great starter bike for me considering I've never ridden a motorcycle before. Unfortunately it went downhill because I have no mechanical skills whatsoever and didn't have the money to just keep taking it...

Not sure how this works im new and i dont understand all the information that has been given to me. wish they made it simpler maybe a book for dummies haha well i just want my bike to be able to cruise at 55 mph without having it at such high rpm's in 5th gear. i have a 1974 ts185. any help is...