Proposing at a young age, like fourteen, can be complicated and may not be the best approach. While strong feelings of love and attachment are common during adolescence, making a lifelong commitment at such a young age can put pressure on both individuals.
Relationships at this age are often still developing and may change as you both grow. Instead of a formal proposal, it might be more beneficial to focus on building a strong, supportive relationship, communicating openly about your feelings, and enjoying your time together. A promise can still be meaningful without the weight of a formal proposal.
Ultimately, what's most important is mutual understanding and respect for each other's feelings and future aspirations.