Hello there,
I know that when you get married and apply for AOS, you can apply for AP too if you want to be able to travel outside of the US. But what about the time between when you enter the country on a K1 visa and when you get married? Is it OK to travel outside the US during that time? And if I wanted to do that, how would I go about it?

There is no restriction on travel outside the USA BEFORE using the K-1 to enter the USA.

Do not enter the USA, then exit and expect to be able to re-enter again though. K-1 is a single entry visa.

How to do it, you behave just as you always have, you get visas for countries that require you to ge a visa, and you don't get visas for countries that don't require you to ge a visa.

once you enter the U.S. on a K1 visa you cannot leave and come back. The AP takes about 3 months from online estimates so it may take even less time.

I meant the period between when I enter the US on my K1 visa, but before I get married. I know I can't enter on my K1 visa again, but is there no other way I could leave the US and come back during that time?

If you leave the USA before marriage, you will have to visit the US consulate where you were issued the K-1, and they MAY re-issue it, the re-issued K-1 will have it's expiration set to that of the I-94 card issued at the POE, the 90 day clock for marriage will not be reset, you have 90 days from first use of the K-1 to marry.

Many consulates will NOT re-issue a K-1 unless the reason for leaving the USA was for an emergency.

The most simple answer to this question is no. There is no way to leave the USA and re-enter using a K1 visa before marriage and AP.

You would be taking a serious risk if you were to try it.

Its not a risk worth taking

OK, thanks for your answers. In that case I won't take the risk.