Am 19 year old guy dating a 17 year old gal. Please, is it a sin? I haven't have any sexual intercourse with her, and I am praying she should be my future wife, if she can wait. Please, am I too young for this? If so, when is the right time for it?
There is no biblical restriction on when a man may date or court a woman. Dating is a time for getting to know another person to consider whether you want to marry that purpose. Therefore, dating should be done with the intention of locating a future mate and not just for personal pleasure.
Nor is there a restriction on when a man and woman may decide to marry. If you are able to support a family and she is willing to work with you to maintain a household then you are old enough to consider marriage. Of course, obedience to the laws of your country must also be considered (Romans 13:1-2); so if your country has age requirements, they have to be followed.
If you are asking if you are too young for sex, it is the wrong question. Sex is only allowed when a man and woman are married and not before. "Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge" (Hebrews 13:4). Age isn't the consideration but your marital status.