Trois phrases parau hasard

"au hasard" would mean "3 random sentences"; "par hasard" would mean "3 Sentences randomLY"

1. Je me suis m'étirée avecde toutes maes forces pour attraper la lame.

It's almost a set expression, "de toutes les forces de qqn"
The object pronoun precedes the auxiliary verb => je ME suis étirée, tu T'es lavé, etc

2. Il boC'est bien que tu arrives à réparer ton toit.

"il est bon" would be very formal and mean something like it's good for your well-being, it's a benefit for you or the community
If you mean you think it's good, in a "good for you" kind of way, it'd rather be "bien"

3. J'ai la donne un chaud accueile lui ai réservé un accueil chaleureux après avoir j'ai entendu dire que son l'étui a lunettes a cassé à cause dus'était cassé dans sa chute.

You can "réserver" or "faire" un accueil but not really "donner'
If you have an infinitive structure like "avoir entendu", by definition you can't have a conjugated form like "j'ai"
For logical reasons, you also can't have a definite pronoun with a possessive : "son l'étui" would be like "his/her the glasses case"
Better to use a reflexive verb when something "breaks itself" => se casser (and we'd have the plus-que-parfait, past action from a past perspective)