Once you've completed Strong Foundations Series 1 and 2 (total of 14 classes), you have learned all the traditional beginner level mat exercises and your TVA and back may be strong enough to move up to Level 2-3. At that next level you start working at improver level and build up towards intermediate.
In order to move up to Level 2-3 (improver-intermediate) you should be able to perform the following levels of exercises:
1. You're able to keep your lower belly (TVA) flat, and your hips and pubic bone triangle alignment flat when you lift both legs up to 90 degrees tabletop position while lying supine (on your back). So for example you can do The 100 exercise with both legs up, at least for 5 full breaths if not the full 10 yet.
2. Your TVA is strong enough to stay engaged (not flop down to the floor) when you do the Swan Dive on your front (prone) and you lift both arms up in the fork positions (elbows bent at 90). In the Swimming exercise you're able to lift your chest, head and opposite arm and leg up without TVA dropping to the floor.
3. In The Shoulder Bridge exercise you're able to lift one leg up off the floor.
4. You are able to do your Push Up in the angle (3/4) position. You don't need to be able to do max rep count though in that position.
If you're unsure, just send me a message or join a premium Pilates Level 1 class or a private premium class and I can assess your level.
Once you move up, you may also find you're able to join Barre instead of Beginner Barre. You may also notice that you're able to choose higher level difficulty options if you take the Full Body Burn class or one of the Pilates with a Foam Roller classes. You can check a weekly routine recommendation I've created here: https://www.annamcleanpilates.co.uk/routines-recommended