1998 honda . shakes as if wheels are lose but all good . at 20 miles a hour.or more . motor runs great .
Well, the obvious thing to do is have the wheels balanced and the alignment checked .
Bring it to an alignment shop. After they find the problems, regardless of what they are it will almost certainly need an alignment anyways.
This is probably not tires - speed is too low. Likely CV joints.
Badly-worn ball joints are another possibility. With a 20 year old vehicle, almost any part could be worn to the point of needing replacement.