Hello HollyHair! (That's a lot of H's) Welcome to the Guild. You'll find that most of us cartographers are perfectionist's too, its due to the nature of the work. We have a board on this forum called Software Discussion - one of the stickied threads at the top discuss many the various types mapping and/or graphic applications used to create maps. While there are several FREE apps available, most have a slight or sometimes steep learning curve. The GIMP is a software very much like Photoshop, only its Open Source, so its free, but like Photoshop it can be pretty complicated. Not to worry though, we also feature a Tutorials board which offer some great teaching tools to build maps or specific techniques for specific kinds of maps.
There are dedicated applications for mapping like Profantasy Campaign Cartographer 3, but that costs around $70 USD. There are mapping apps like AutoRealm that is free, but they are very limited on what they can do and may not have the best support and resources.
It depends on what styles of maps you want to develop. Some are stamping apps, some are image editors, some are vector drawing apps. Each have their strengths and weaknesses - it really depends on you.
We have several Scots and Brits here, I don't know if we have a specifically Irish member yet - though I'm American, my last name is Tumey (so I'm Irish too.)
If you have specific questions about specific software, ask them in the Software Discussion Forum. Once you decide on an app, go for the tutorial section and try all the tut's for your application of choice. Though some of the tutorials are for types or techniques you many not immediately need - you can really learn how to use the software for your own needs, once you learn the tuts. So do that next.
Once you start creating your maps - post them in the appropriate WIP forum (work-in-progress), we'll be waiting with baited breath to give you advice, accolades and critiques, which is a great way to learn so start posting your maps early, no matter how bad you think they are at each stage.
Again welcome to the Guild!