See this guide: https://forums.dolphin-emu.org/Thread-laptop-performance-guide
The trick is, after you do everything specified in the guide, don't touch the Adapter settings in Dolphin. As for settings, try increasing the IR to 2x or 3x. If you notice any slowdowns, scale the IR back. Then add AA if you feel the need to. Again, if you encounter slowdowns, scale back the AA. Note that LoZ:TP gets very demanding later on in the game (Hyrule Field specifically) and there's nothing your GPU settings will do to fix any of those slowdowns.
The trick is, after you do everything specified in the guide, don't touch the Adapter settings in Dolphin. As for settings, try increasing the IR to 2x or 3x. If you notice any slowdowns, scale the IR back. Then add AA if you feel the need to. Again, if you encounter slowdowns, scale back the AA. Note that LoZ:TP gets very demanding later on in the game (Hyrule Field specifically) and there's nothing your GPU settings will do to fix any of those slowdowns.