It's definitely doable yourself, and once you've done the first one it really is not complex at all. The learning curve is quite steep however, there is a lot of jargon unfortunately!
You could consider paying an accountant to do it for you the first year, just to give you an idea of what is supposed to go in each box, then do it yourself in subsequent years? It might cost you €3-400, but this is an expense so is tax deductible and it's quite likely in your first year that the accountant could end up saving you close to that by telling you about things you can claim for, extra expenses you might not be considering etc.
Either way, the more you can do during the year by tracking all your income and expenditure in a spreadsheet the easier it will be come tax return time, so record everything!
Note in October of 2019 you would be doing a tax return only for October/November/December 2018.
Revenue will also ask you to take a guess at your expected income for 2019 and pay that in advance (preliminary tax).