Here are some common settings...
Monthly recurring, with no trial or 30-day trial:
Recurring Cycle #1: 30
Recurring Cycle #2: 30
Recurring Cycle #3: 30
Monthly recurring, starting with 7 day trial
Recurring Cycle #1: 7
Recurring Cycle #2: 30
Recurring Cycle #3: 30
Monthly recurring with first one 7 day trial, followed by another 14 day trial
Recurring Cycle #1: 7
Recurring Cycle #2: 14
Recurring Cycle #3: 30
Explanation
When someone subscribers to your recurring product, you know that you will receive a first payment, a second payment, a third-payment, a fourth payment, etc. If you have unlimited recurring, then you will get payments forever, until they cancel.
So just think of the first 3 payments:
Payment 1 (happens today)
Payment 2 (comes in after X number of days)
Payment 3 and onwards (comes in every X number of days)
So when someone first subscribers to your product, however many number of days you wish to give them access, enter that number into recurring cycle 1.
When their next payment comes in, however many number of days you wish to give them access, enter that number into recurring cycle 2.
And when the 3rd payment (and onwards) come in, however many number of days you wish to give them access, enter that number into recurring cycle 3.
In 99.99% of the cases, Recurring Cycle 2 & 3 will be the same. The only reason we have separated them into two, is just in case you wish to offer 2 trials.