What can I do to have my destination confirmed?

To gain a secure destination, one needs to enter tje stream, good householder, and here a set of collections of the Buddha, how to gain it: Into the Stream: A Study Guide on the First Stage of Awakening.

(Note: this is not given for insecure destination by exchange, staks, and trade binding, intended, for the world, but for the secure destination of lasting liberation from this wheel: to bind toward Nibbana for those able to take the gift)

Im not sure about guarantees but there are these relevant passages;

Association with people of integrity is a factor for stream-entry. Listening to the true Dhamma is a factor for stream-entry. Appropriate attention is a factor for stream-entry. Practice in accordance with the Dhamma is a factor for stream-entry. — SN 55.5

There is the case where a monk remains focused on unattractiveness with regard to the body, percipient of loathsomeness with regard to food, percipient of non-delight with regard to the entire world, (and) focused on inconstancy with regard to all fabrications. The perception of death is well established within him. [One such as this] attains the immediacy that leads to the ending of the effluents. -an4.163 (excerpts)

Admirable friendship, admirable companionship, admirable camaraderie is actually the whole of the holy life. When a monk has admirable people as friends, companions, & comrades, he can be expected to develop & pursue the noble eightfold path. -sn45.2

When, on observing that the monk is purified with regard to qualities based on greed, qualities based on aversion, qualities based on delusion, thinking: 'There in this venerable no such qualities based on greed, anger or delusion, with his mind overcome by which qualities, he might say, "I know," while not knowing, or say, "I see," while not seeing; or that he might urge another to act in a way that was for his/her long-term harm & pain he places conviction in him.

With the arising of conviction, he visits him & grows close to him. Growing close to him, he lends ear. Lending ear, he hears the Dhamma. Hearing the Dhamma, he remembers it. Remembering it, he penetrates the meaning of those dhammas. Penetrating the meaning, he comes to an agreement through pondering those dhammas. There being an agreement through pondering those dhammas, desire arises. With the arising of desire, he becomes willing. Willing, he contemplates (lit: "weighs," "compares"). Contemplating, he makes an exertion. Exerting himself, he both realizes the ultimate meaning of the truth with his body and sees by penetrating it with discernment. -mn95 (xcerpts)

As to related question. The analogical reasoning in the sutta is smth like this 'there are dangers on the journey, as there are for a sailors; sharks, waves, weather and whirlpools . That some warriors tremble and run away hearing drums of the enemy, some tremble at the sight of their banners, some are defeated in hand to hand combat, some get injured and recover, some get injured and do not recover.'

I assume many things may cause one to disrobe, longing for this or that, perhaps one has to take care of parents.

If one disrobes it doesn't necessarily mean that one's practice stagnates. I think pali lore has a story of a monk disrobing, becoming enlightened and rejoining the order.

Well, you forget everything you learned because you lack mindfulness. Loss of mindfulness is precisely what you described: forgetting the teachings.

You can't have your path confirmed. Advanced practitioners can tell you there opinions, but not confirm your level of attainment.

To define stream entry and the way it occurs is a rather arbitrary process, but I shall go on to do so anyways. Keep in mind, that a sotapanna can doubt their attainments because there is so much misinformation on what consitutes entering the stream. Only the Lord Buddha can definitively tell the attainments of another...

On stream entry.... One such way to describe stream entry is by getting into a state of meditative absorption, a great rapture will invade one, and a strike of luminosity (metaphorical and literal.) It is the attainment of samadhi, and consequent knowledge of anicca.

There are dhamma-followers and faith-followers. I don't know if they are sotapannas or not, but they are mentioned in the texts by the Lord Buddha. They seem to be culasotapanna (lesser stream enterers)(???):

Dhamma-followers are those that have reflected upon the dhamma and grasped it as correct. Faith-followers are those, that out of their faith in the Lord Buddha, have attained something (I don't know if this is the attainment of stream entry or not. I won't comment because I'd hate to spread misinformation.)

The characteristics of a sotapanna:

1. Perfection in keeping the Five Precepts
2. They have an intuitive grasp of the dhamma, but still fall prey to desire, aversion, and delusion
3. Buddhism is their life. It is a true refuge : that which they can rely on at all times
4. Confidence in the Buddha, Dhamma, and Sangha
5. Complete elimination of a sense of self consistent across time.
6. Complete elimination of a self inherent in any of the aggregates

Finally, I want to pose the question to you, what do you hope to benefit by getting a confirmation of your attainment? An ego boost? Wanting to have something to "show" for your practice?

Being a sotapanna doesn't matter if you still have suffering.