Oxygen Header Image Center Align

Hello,

I’m a very new WordPress user. I have moved my blog to self self hosting it with blue host. I still have the same theme – Oxygen – but because I am no longer operating in wordpress.com I don’t have the option to easily add a header image.

Ideally I would like to have my header image large and be centred rather than left aligned.

Any help would be appreciated!

My site (early stages progress): https://www.bohemiantable.com

Thanks