Did anyone get into teaching later in life?
Yes, I am 39 years old and I am just about to complete my first term as a trainee teacher.
I’m only mid 20s
You are just starting out, I would definitely say that you are not "later in life". The other trainees on my course range from 22 - 55.
I don’t know if this route would go against me when applying for teachers?
In some respects I would say that the opposite is true, in that working for and graduating from an OU degree takes dedication and perseverance.
Also, if you manage to complete a degree when you have a family to look after it shows that you can manage study and caring for them.
How would I go about doing an Experiance day?
Once you are applying for a place on a teacher training course, you can arrange these through the DfE but I don't think that any schools would be willing to do this for someone who is not ready to apply yet.
What you could do is to speak to your child's school and ask them if they could accommodate you or if they know anywhere that could. (When I say "speak", I mean write a letter or email)
didn’t manage to get any qualifications behind me
When I was your age, I had:
10 GCSEs (all A-C except Music D) and a Diploma of Higher Education in Law
(Basically I did a law degree and never sat my final exams so instead of getting a degree I was awarded the DipHE)
I did not graduate from my degree until December 2017
BSc (Hons) Computing & IT from the Open University