Welcome to ECF! We're glad to have ya.
Good luck on your DIY journey! Be careful with FA flavors... They are very potent, so start at 1% flavoring, maybe even 0.5% and adjust to taste.
Also, the only other advice I can give... Start mixing by following tried and true recipes. I dumped so much
juice down the drain because I thought I could just start free mixing the second I got the flavors. After a while, you will start to find which flavors work well together and at what percentages, then you can start working on some of your own stuff.