buy a little every month and let it accumulate. in the long run you will do well

$BTC
At the beginning of the pandemic, I bought 30 euros in Bitcoin. Years went by and I never remembered it again. Last week, I was talking to a friend and he reminded me and, to my surprise, I had doubled 100% of the amount invested. This is my portfolio right now. I don't know anything about investing and buying cryptocurrencies. I have been studying but there are many technical names that leave me quite confused. So I came to ask for your opinion. What do you think?
Please don't be mean with your comments. I just need advice, not insults or discouragement.
Thank you