As an exchange student from one of our Erasmus+/Swiss European Mobility partner universities you will not have to pay any tuition fees at Queen Mary.
Regarding your Erasmus+ grant you will have to get in touch with your home university as the grant will be paid by them and not by Queen Mary.
Queen Mary's Advice and Counselling Service has a wealth of information and advice on various topics to support you during your studies and life in London, in particular with regard to finances, budgeting and banking in the UK. You can prepare for your stay with us by visiting the below pages:
Also, we have some tips on how to make the most of you time in London (and save money) here: London on a budget.