So, I'm new to Pokemon Mystery Dungeon speedrunning, is there any strats or things I should know before I do a run?

I'm assuming you want to run any% no WM (the only category for now).

• Options: Change speed to fast, camera off; auto mode focus to finding the stairs, auto mode movement to fast
• Linking moves is free at Gulpin; losing PP will NOT delink moves. Based on the moveset of the starters that you chose, link moves accordingly; learning a new move over a move part of link will delink the move.
• There are a lot of mission days that can be skipped by Giving Up in a dungeon. Make sure to store your items and money first! On one of the mission days after Mt. Steel, you can access bank/storage directly from the dungeon exit instead of going to town (and avoiding dialogue)
• Try and find Blast Seeds for early bosses. Having Linked Moves is essential.
• Absol carries after Mt. Freeze; try and find a Brutal Swing TM in shop (not required).
• Rescue Team Base upgrade requires 3 Chestnuts instead of 2; Uproar Forest is only 3F instead.

I think some people in the community will gradually put together a written guide; here are my few cents as of this very early stage.

Okay, thanks! I already knew about the Auto Mode thing (Stumbled upon it in the settings), but I didn't know about most of the other things.

Oh, and what do you mean by "link moves accordingly"?

Teaching a move over a linked move will delink the whole set. Say you start with Meowth and link Scratch + Bite + Foul Play. At level 14, if you wanted to teach Fury Swipes over Scratch, that would delink the entire moveset. Luckily in the fugitive arc (Lapis Cave - Mt. Freeze) and onwards Link Boxes spawn fairly frequently so carrying 1 to relink moves as necessary is recommended.

I should also add that there doesn't seem to be a way to speed up move animations in this game (unlike Gates), so finding ways to link as few moves as possible while doing enough damage is ideal.

is all icons mean all the legendary and mythical battles then?

yes

no

I got farther into my normal playthrough, and I realized that encountering Munchlax gives you an icon, and so does unlocking Smeargle. So, it's not just all the legendary/mythical bosses.

i found out its all main story line encounters