thank you for sharing your question with us in the community.
The marriage wont change anything, unless your girlfriend applies for family unifiaction.
If she does that and she can provide financially for both of you, then your visa application for the UK might be successful.
However, due to the rigid migration policy it might be quite difficult.
So the best way would be if you are a skilled person to find a job and then apply.
I hope this could help you, if you need further clearification please do not hesitate to use our community.