spray the moving parts with WD 40 (wd stands for water displacement even though it is usually used as a lubricant) cover with a tarp but leave the bottom of the tarp open to help prevent condensation. In times of good weather use them and respray. Congratulations on trying to take care of your bikes. Most bikes age because of lack of care and not abuse. ps a light spray is better than a heavy spray.
wipe the sheet metal with a cloth dampened with wd 40 one of the new microfiber cloths is very good. Keep the damp (not wet) cloth in a closed glass jar.