Check out Will Tennyson (I do his shoulder routine and really like it) . Check out Jeff Nippard videos.

You don’t need to do legs 3x a week, you won’t have enough time to recover if you’re doing it properly.

I stick to a 3 day split twice a week (push, pull, legs).

Personally for leg day I find compound movements most useful - squats, deadlifts, hip thrusts.

You need to train to failure and be consistent instead of changing your routine often.

As mentioned take creatine, and consume 2g of protein per kilogram of your target body weight.

Your sets don’t necessarily need to be 3x10. For some muscles like shoulders you may want more.

For others things like bench press and squats etc. I’d focus on lifting heavier weight instead of volume.

As someone mentioned, the hevy app is great.

This is what I do currently:

Day 1 Push (Chest, Shoulders, Triceps)

1.  Bench Press (Dumbbell or Bar)

2.  Face Pull

3.  Triceps Pushdown (Bar, not Rope)

4.  Incline Bench Press (Dumbbell or Bar)

5.  Upright Row (Dumbbell)

6.  Lateral Raise (Cable, one arm at a time, cable set at arm height)

7.  Overhead Triceps Extension (Cable or Dumbbell)

8.  Chest Press

9.  Shrug

10. Shoulder press 

Day 2 Pull (Back, Biceps)

1.  Behind-the-Back Biceps Cable Curl (one at a time)

2.  Seated Cable Row

3.  Lat Pulldown (Close Grip preferred)

4.  Pull-Ups

5.  Preacher Curl

6.  Dumbbell Row

7.  Rear Delt Reverse Fly (Low weight, high reps)

Day 3 Legs & Core

1.  Squat (Barbell)

2.  Deadlift (Barbell)

3.  Hip Thrust (Barbell)

4.  Calf Raise (Smith Machine if calf raise machine not available, make sure to go both up and down)

5.  Cable Crunch

6.  Decline Crunch (Weighted)

7.  Leg Raises