The wrinkled carpet can only be fixed by stretching it out again. Training and persistence are necessary for re-stretching. There are times when the initial stretching of a rug is more accessible than the subsequent re-stretching. As time passes, the carpet will buckle where the ripples have been disregarded.
Use fabric glue to permanently fix tears, sew hems and seams, and glue and seal braids and trims. It's machine-washable, dries clear, and maintains its flexibility.
Baseboards are not removed. Ask the baseboard installer to provide a 1/2-inch gap between the floor and the trim before laying the carpet.