It is better to avoid the pronoun "we" in your writing (the possessive pronoun "our" is ok). If you want to give an overview of your paper or approach, use "this paper" or indicate a specific section instead:
We introduce ... -> This paper introduces ...
-> This section introduces ...
We present our transformer model in Section 3.
-> Section 3 presents our transformer model.
Use passive voice to describe your methodology or findings:
We use a transformer model to ...
-> A transformer model is used to ...
We collect 1,000 posts from ...
-> 1,000 posts are collected from ...
You may want to use the pronoun "we" to distinguish discussions or notes that are helpful but do not necessarily contribute to the general knowledge:
Note that we also experimented with ... that did not show a better performance.
Use the present tense to describe your work:
Three models were developed for ...
-> Three models are developed for ...
Use the past tense to describe previous work:
Chen and Choi, 2016 introduced ...
In our preliminary study, an accuracy of 92% was achieved for ...