In the past 1.5 years I went from over 300 to 250 pounds using a combination of better eating, no pop or alcohol and putting over 100 miles a week on my bike (thanks to covid working from home ) I'll be turning 49 this year.

In the new year I'm looking at adding light weight training. I'm looking to add some strength mostly core to help with past back problems.

The only gyms in town are the Anytime type. I've been reading about sandbag training and wonder if this is the better way to go.

So I'm looking for advice if the gym would be better or get some at home equipment.

Any reason you're avoiding traditional barbell strength training?

I have and have used lots of equipment.  However, two or three kettlebells used wisely can do most anything you need.

If you are rooted, and have the room for it, you can't beat a home gym.

Can be a little pricey, but a rack, some weights and a bar, and maybe some dumbbells or kettlebells will do a lot.

For core training and back problems, I would look into kettlebell training.

Inversion table, and reverse hyper can be magic with back problems, if you have the space and budget.

For your use, get a 30-35lb kettlebell and start doing Simple and Sinister (100 Swings and 10 Turkish Get Ups). It’s a quick workout that will let you build up some work capacity and core strength. Get a coach to run you through both movements.

After 6 months, add a 53lb bell and keep going. Then a 70lber after another 6 months.

From there you can look at barbell work (or before, it’s not a prerequisite) and learn the basics, Squat, Deadlift, bench, and OHP. Higher weights for shorter sets.

So I've decided to get a gym membership so I have more access to equipment.

Where is a good place to read about setting up a couple lifting routines and ser/rep for starting out?

Starting Strength
Stronglifts 5x5

Was going to say kettle balls.  You only need a few

I like using machines since I can get in and get out without relying on a partner for spotting. Just make sure that any routine is hitting all the muscle groups you need to exercise. I do supplement with free weights for shoulder shrugs, and bands for working the rotator cuffs.

I like both barbell training and sandbag work. Pick up a light sand bag, and do barbell training first then finish with a sandbag.

^^^This is the answer.  I have a squat rack a couple benches, couple barbells, adjustable dumbbells, and all the weights I need.  That's it nothing fancy.  For a busy life style it's the way to go.  No time wasted driving to a gym or waiting on other people or being distracted during a workout.  Never have to be rushed or worry about forgetting something like my EAA's because everything is right here at home.  Workout when ever I'm feeling it.  Want to get a quick pump after a big carb loaded supper go grab a barbell and do a few sets.  

The convenience and lack of dealing with the public or distractions has been huge for me.  I never miss a workout ever and I can always have a meal pre and post workout on time every time.

I was done in 30 minutes today.

I hit a top set on rows and squats, then just worked triples until I didn't want to anymore....then ate a half a sub I found in the fridge.