if you say you are late joining and getting to know cryptocurrency, maybe this is a good time to start again, because in the next few years I believe that bitcoin and other altcoins will reach their ATH again
Well sure at some point they might reach their ath as you say, and you mention it will happen in the next few years. It might happen a lot sooner than that and it might not happen for a very long time. We just don't know when, all we can do is guess.