Welcome to the guild, PaGaN, and what an impressive start! You asked for some advice/feedback regarding tectonics, so here goes:
First off, I need to give the usual disclaimer that getting the tectonics to a sufficiently realistic level where it starts to feel like your world is actually comparable to Earth, is a pretty big undertaking. However, if you're willing to go through all that hassle, I think the key advice is to consider your "present day tectonics" as only the latest stage of a long process. In other words, for things to be realistic, they need to have a geologic history. Where was X piece of land located previously, and how did it end up in its current location?
One of the ways to accomplish this is to create a GPlates model of your world's geologic history, for which there are a few handy tutorials by Astrographer.
However, while GPlates provides the tools which allow you to move continents and pieces of continents around, if you're going for ultra-realistic, you kind of need to have an understanding of Earth's tectonic history in order to have a clue about how they should be moving. You can check out Christopher Scotese's Atlas of Plate Tectonics Reconstructions for some handy advice. Scotese also has a youtube channel, with several videos about continental drift, this one, for example. Another tectonics-related youtube channel is EarthByte, which likewise has videos of several plate tectonic reconstructions (example).
I'll try to provide some actual feedback at some point, but I think those links should get you started, and I don't feel like writing a massive wall of text at the moment (tectonics-related posts have a tendency to become really long ). Good luck with your map!