We can outline the passage like this:
An overview of Paul’s initial ministry in Thessalonica (1 Thessalonians 2:1–4)
The nature of Paul’s entry into Thessalonica (1 Thessalonians 2:1–2)
Motivation for the claim in verses 1–2 (1 Thessalonians 2:3–4)
A detailed description of the ministry (1 Thessalonians 2:5–12)
1 For you yourselves know, brothers, that our coming to you was not in vain.