Welcome to the site, and to the hobby too by the sound of it. You WILL find coins soon, that's a fact, so don't worry about that.
You're unlikely to be "told off" while detecting on a beach in the UK, however, ALL land has an owner and you DO need permission by rights. For beaches this isn't a big problem as most are owned by the crown (Queenie)...and a printable permit can be gained in a couple of minutes online here:
The Crown Estate || Metal detecting
Public land such as parks etc are another thing altogether! While it's possible to detect them without "permission", people can and will sometimes give you grief for detecting there, especially if they're park wardens, council officials, police etc. Applying to the council for permission generally ends up in a refusal as they don't detect themselves and assume you're going to dig your finds up using a JCB! So the rule of thumb in parks is...do it until (officially) thrown off!

If you live in North Yorkshire, then you have massive amounts of history buried and waiting for you to stand in the right place with your detector. Possibly you live near farmland and as you progress into the hobby can ask or get a farmers permission to detect his fields...these are by far the best places to detect and the places with the best finds.
Best of luck to you in the future and don't give up. Detecting is a frustrating hobby at times, but one of the most rewarding for the patient.
Feel free to post anything here for us to guess at and/or solve for you and don't be afraid to ask questions.