There are a few things for you to think about here tbh.
SWs will want the child to have a secure, safe home which in reality means enough space for everyone that lives there eg a bedroom for parents and a separate room for any child placed. You sleeping in the living room might work for you, but add in a child, their toys etc and your living room becomes a living space and you lose your privacy (which you will really need parenting an adopted child).
Your weight doesn’t need to be under 30 but being able to show weight loss over a period of time, having an active lifestyle, and a good understanding of nutrition will all be important because children may come with complex issues around food that you need to be able to support. Having good processes around preparing and eating meals is all part of that (ie having a table to eat at).
Childcare experience isn’t the same as parenting and I have my own views about how useful it is to ask for but I’d ask them specifically what they want you to be able to evidence (eg providing practical care, building relationships, play) and either show how you have this already or find a placement that fills those gaps. Think about the age of children you’re hoping to adopt and volunteer with a relevant organisation.
Autism is absolutely relevant in adoption, especially if you’re looking to parent a child who may have their own difficulties around communication, social skills or relationships. Think about the degree of complex needs you might be able to support - being honest about the impact on you. For example my DD has very complex needs which aren’t apparent on meeting her but it means I can’t work full time, she needs a lot of emotional support and practical support, has a lot of health appointments etc.
Adoption is about finding parents for children, prospective adopters need to consider how far their current lifestyle may need to change to support the varied needs that come with adoption - its not remotely the same as parenting a birth child so things that might be ok for a birth child (parent sleeping in living room) really wouldn’t be for an adopted child.
Do some reading on developmental trauma, therapeutic parenting and attachment so you’re more informed about what might lie ahead.