Blog Page shows up as jumbled mess in internet explorer & firefox browsers

Hi there
I have just been notified very kindly by a customer that the blog page section of my website shows up as a jumbled mess when viewed in internet explorer and firefox (I don’t know about any others yet) The writing is going over the pictures which are much larger than they seem to be when viewed on my computer…I use google chrome, everything shows up ok on there, and on my mobile phone

Can anyone help please???

Many thanks
Michelle