from my mod q
ok first of all there's a dedicated forum for finding bpm offset https://osu.ppy.sh/community/forums/topics/13795?n=1
second of all, realistically speaking, this kind of song that's very likely live performed is super tedious to time because without extensive editor like ArrowVortex, you have to place notes every 1/1 or even more snap to make sure the timing is correct while fine tuning the bpm lines which is a lot of effort.
which if isn't obvious enough, wouldn't be the kind of song I would recommend a new mapper to try and chart. I'm sadly not the right person to ask because I did not really intended my mod q to check timing points (I focus more on chart patterning in general)
this isn't meant as a discouragement but like. reality check. a map that isn't properly timed isn't pleasant for modders to mod so, that's one thing. and as a new mapper, I think it's much more beneficial for you to try charting some songs with sensible timing. so that you can actually focus on asking for pattern/chart feedback instead of being stuck at timing points. (you can ask again in my queue if you ever have the chance to again)
Tho I gave it a try to time myself and it is definitely not just 2 bpm btw. like my go-to advice is to time to the instruments since they're usually consistent. Do not ever put timing points based on vocal unless there's no other instruments to refer from.
but I guess even the instrument is live performed for this song while I tried to time it. I couldn't really decide if the bpm is 112 (56) or 113(56.5) for most of the song either.
At the very least I think the beginning timing of the song would look something like this https://pastebin.com/3NAFi5Ze. (Just download the file and put it in your beatmap folder)
good luck