Hi Sara
Welcome to the forum, they are a great lot here.
I was new not that long ago, i would second the specialist running shop information as this is a must.
I did a ten mile race yesterday and come along a man (another runner) whom was walking i asked if he was ok, he said his calves were killing him.
When i looked down he had tennis shoes on, how can you possibly run 10 miles on tennis shoes, no wonder why his calves were killing him.
I edged him on to finish it together (this was 8 mile mark) but he could not keep up.
I told him in a round about way if he been to a specialist shop to have his shoes looked at, because i knew it was his shoes.
He had done half marathons before and he was part of a club, so he was not new to running.
Why put yourself through that pain
he thanked me when he finished for trying to lift his spirit but really it was self inflicting.
So definately a must is the right shoes Sara.