I (F38) am socially awkward, started a new job with colleagues who are close and starting to treat me as a friend, I haven't had any friends in a long time, have no idea what to do

I am really hoping someone can help me with this. I'm very socially awkward, from childhood, but made worse from an abusive (emotionally/mentally controlling and intimidating) relationship. The only friend I had was my ex's friend which fell apart after I got away from him.
My last job had lots of client contact which was fine as I have a "professional persona" that I put on, and I had an office to myself that was out of the flow of traffic, my colleagues often forgot I was there. I tend to self isolate anyway so didn't often join for lunch or other breaks.
I recently started a new job which I absolutely love, but it's an open plan and the current staff (all female) are very close.
They are so lovely and inclusive of me and have friended me on fb and I have even exchanged numbers and texts, all initiated by them, even picking me up something on their morning coffee run before I get there.
They obviously care about each other, and are showing the same interest in me, but I've got zero social skills. I find myself spending the conversation planning what I should say to show the appropriate amount of interest without being nosey, or what I can say to sound interesting so that they will want to keep talking or monitoring my facial expressions, and as a result sometimes miss what they actually say. It all sounds very weird, I know.
I've spent years being made to feel like my needs are less than unimportant, so to have them consider me (staying back to wait for me when I'm running late etc) I feel anxious, like I'm putting them out.
I've been in therapy for the last 12 months and come a long way, but due to my new job I am not able to go very often.
I have always wanted friends, especially women friends, but I've never had the courage to pursue anything due to not knowing what to say and feelings of worthlessness.
I tried bumble bff and all the women I've matched with and started conversations with have just stopped responding (8), so I feel like I don't have much to offer or I'm very interesting.
Is there anything I can do to improve socially? These women are so lovely, and I feel so excited they are so welcoming and wanting to be friends, I'm just scared I'll do or say something weird and freak them out, I just want to be a good friend.
Sorry this got kinda long. I hope I don't sound too weird, twelve months ago I wouldn't have been able to get this far, my fear and awkwardness made me come across as cold and uninterested. So this is pretty huge for me.
Tl:Dr I'm socially awkward and having trouble navigating new friendships


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