if you've taken care of turtles i think you'll find tortoises will be an easy transition i keep sliders and box turtles so i know the differences between terestrials and aquatic turtles. basically you'll have to read up on the dietry needs of whatever tortoise you pick and humidity and lighting but after that you'll be open to any kind of tortoise you think would be best.
i'd say turtle and tortoise eggs are pretty simular it just depends on the species. turtle eggs seem to take less time to hatch because some tortoises have really long incubation periods.