OP...sorry to hear about your losses 💗💗.
Beat going over to the adoption board as this will get flooded with posts from people saying "adoption shouldn't be a last resort" "adopted kids will all try to kill you in your sleep" and other horror stories ;)
Briefly, the adoption process to become approved goes like this:
Telephone the agency...usually people go through their local authority...Google your council and adoption and it will come up
You will be invited to an information event where you can find out more about the process
Stage 1 of the process is medicals/finance check/references (work and personal), DBS checks
Prep training..usually around 3 full days
Stage 2 ...assessments visits with your social worker
Approval panel...where you go to panel and they approve you as an adopter
All of this aims to be done in 6 months but can take longer.
Wait to be matched with a child...this is how long is a piece of string.
Then matching panel.
Introductions with little one...roughly 2 weeks or so.
If your most recent miscarriage was recently then you will need to take a period of time between that and starting the process. That period of time will vary depending on your local authority or agency. In the mean time do a lot of reading on attachments and trauma in early childhood. Adoption UK is a good place to start as is the prospective adopters group on FB.
Best of luck if you decide to move forward 💗