Welcome to the forum and glad you are here.
There is a special area especially and specifically for partners and significant others that you may find helpful as most have been in a similar position as you are in now. – look in the group area for the link or contact one of the administrators for more information.
One of the issues with being TG/CD is that we don’t always know how to explain how we feel, what drives us to dress. There is often a large amount of guilt and remorse when compelled to dress and that is hard to come to terms with. Often we don’t know ourselves so it’s nearly impossible to explain to others about our feelings.
You are already half way there in taking the steps to support your partner and find out more, which is already an amazing thing that many don’t have, so well done for taking these steps.
The big thing for my partner and myself is to keep talking and be receptive. ask them about what they would like to do with their dressing and how they would like to develop it. There may be a need to compromise and set boundaries, but this is often something that needs to be reassessed and reset to keep things in perspective.
Being CD/TG can often be progressive, where each ‘adventure’ builds on the last. starting with underwear in the bedroom, then adding clothes to wear indoors, and maybe progressing to going out fully dressed. Some never go this far while others find there is a strong need to fully dress in public etc … we are all unique so there is no ‘one size fits all’ description.
I hope that helps and I know that others will come to offer their input here too – but I know that you are not alone with us and the rest on here to support you