I believe the technology in new clubs benefits the 8 - 24 handicapper the most. Higher handicap players have such an inconsistent swing their problem isn't likely the clubs. As you get below an 8 your swing is probably consistent enough that you could play with any clubs and have decent results.
Absolutely start with lessons as you don't want to practice an incorrect swing. You are in a good situation for lessons, since it's been so long, perhaps you won't have to correct bad and ingrained habits.
I'd say don't even take a swing until you are with a good instructor.
I believe you can place something on the ground to help with alignment, but you have to remove it before you make your stroke. Or, for instance, your partner could stand at the top of a hill while you line up, and then move out of the way before you hit. I believe that would be similar to using a club for alignment, and then removing it before the strike, which is allowed.