I don't know which stock to buy now ...

Hi everyone, I've got some amount of euros to invest in stock market. But to be honest, I don't know what I can buy for 2026. Everything seems so expensive. I bet on Credo and Astera labs for AI networking : stop loss reached. I bet on defense like redcat holding and kratos but stop loss reached. And the worst, they have all pull back just after touching my SL. I try to keep it good because i saved some money but it's everytime the same s:it. The stock loses 10-20% and after everyone sold, rebound ... Today I don't what I can buy to bet on AI. My AI memory stock were well (particularly today), but I hesiste to pay after this strong pull. I don't like GAFAM. I'm not a big fan of their business plan. I prefer to bet on people who takes the money lol My main problem was my past with stockmarket, I got so bad surprise, even if the company is good. Today, i'm losing 15% on Innodata. Everyone said the company is great, they announces new big deal everymonth, but no, the stock dropped. And because I didn't put a SL, i'm loosing too. I made the same mistake with AMD at the end of 2024 : Everyone said AMD is great, but finally, I have to wait 8 month to see AMD make a come back at my PRU. So do you have some ideas ? thank you :)