Post lesson 1 for official critique, then wait for your critique to come in. Normally you're supposed to do another 50 boxes if you finished the challenge before critique on lesson 1 but you can ask if they'll let you submit it if there's no significant problems with your lesson 1 submission.

The reason they don't let you submit later lessons before critique is because if something goes wrong in one lesson that has a knock on effect on the others, making critiquing them pointless since they'd just be reiterating about problems you already know are there.

What SomethingX stated is largely correct. You'd start by submitting your Lesson 1 work, as-is. Any required revisions will be assigned if they're necessary, and once it's marked as complete, you the system will indeed force you to wait 2 weeks prior to your next submission. This is both so students don't rush their work, as well as to ensure that our staff is not overwhelmed. Having people complete the work ahead of time and submit rapid-fire is very much not what we're able to handle.

Normally work done prior to having a prerequisite marked as complete is not accepted, but the box challenge is an exception in which students are only to complete an additional 50 boxes after having Lesson 1 marked as complete - so you'll be able to spread those out in the 2 weeks after your Lesson 1 work is marked as complete. That, alongside adhering to the 50% rule from Lesson 0, should give you plenty to do in the meantime.

After the box challenge is marked as complete, you'll be able to continue on from there, starting on your Lesson 2 work.

If you want to do official critique you will have to start over as you did 250 box challenge. You might not need to redo lesson 1 homework and can submit it for review. the requirements will be more strict so they can give you feedback.