Havent lifted weights in years. Didnt need to till this new computer gig. Now even suitcases are heavy. How to regain strength?

Just start. The key is to start. Start light and focus on good form. Add volume and intensity slowly. The first goal is to avoid injury. The second goal is to enjoy yourself. Try lots of different exercises. There is health benefits to variety, plus it keeps the workouts fresh. Get a good mix of pushing & pulling exercises, arm & leg workouts. Don't forget your core.