You learned a very good lesson from getting burned. You learned what a bad business investment looks like. Go over why your first investment failed to learn what signs to look for when investing in the future.
You have to fine tune your b.s. meter. Unfortunately , this usually involves being burned at LEAST once.
Investing is gambling- do not invest more than you can afford to lose. It may be the next big thing or it may be a flop. Even if it is the next big thing, it could wind up a flop if people are idea plentiful but fiscally foolish.
Don't get emotionally invested in the project. Ask for a business plan. Does the person whose thing you are investing in have skin in the game, have they invested any of their own money in the project? Are they talking to other investors besides you?
Talk to outside people about the project ( don't get specific , but enough general details) to see how the purchasing public reacts- does it hold their interest or are they saying "meh...".
To be a successful investor you must be willing and able to assume and absorb financial risk. You have to have enough of an ear for what people really need/want that your gut says "yeah, this WOULD be a good investment" or "meh, not worth it".
Don't be demoralized by the first failure. Everything is a learning curve and now, in your brain are certain alarms that will sound if they happen again. Good luck !