Welcome to the website!
Yes, some of the spells that are here can come true. Some and can being the keywords here. Not all the spells here are true, as anyone can become a councilor in some of the covens on this website (and not just Spell Casters) and begin posting spells. Remember to keep within the realm of reality and personal safety and you will do fine. The can part is totally dependent upon you. If you are unsure of how to properly cast a spell or do a working (even if there are instructions for them), there is no guarantee that the spell will work on it's own.
I would start with simple things, such as meditation, visualization, and energy flow and control, and once successful with those, move on to doing spellwork and such. :)