Yep, you need to juggle them. Deadlines can and will clash and it's up to you to manage your time and keep on top of it. Each module's website acts as a handy interactive calendar, which helps- you can check what material you should have covered by when, check off each part as you complete it, etc. Just count yourself lucky you have 2x60 credit modules rather than 4x30!
There are a handful of exceptions (TM111 and 112 are studied sequentially for example, and sometimes staggered starts are possible).