First of all Welcome Millie to huge Forum of like minded people who have a wealth of knowledge.
It sounds like you have your hands full, First of all take a deep breath!
Sadly in alot of cases Technical is the unloved child of a buisness as to meet requirements its vital but at the same time doesnt make money its just costs it. Its not unusual to be in this situation so dont worry you are in the right place!
First of all try and get management commitment, maybe put a little presentation together and explain what you require/support you need to achieve great results and ultimately the results they want!
Look at the requirement of what you are trying to achieve and break it down into small bite sized pieces, i had a quick look at their website and its broken down into sections as you would expect so tackle them individually. It looks like they can give you advise too.
If you can, put a team together and have regular meetings so you can get feedback and the buy in from certain areas of the buisness.
Regularily feedback to the more senior team so you can highlight areas of weakness.
Do a gap analysis or get an external auditor to do one for you, its sometimes good to have someone from the outside come in and tell the management where the issues are and push you in the right direction.
Dont over complicate it, if policies / procedures are simple and effective they are more likely to get done and achieve the results you require.
Hope these few suggestions help, it does seem a huge challenge but im sure you will smash it!
If you need advice on specific issues, im sure there are lots of people on IFSQN who would love to help