وَتَصُومَ رَمَضَانَ names fasting in Ramadan. Fasting brings together intention, prescribed times, and restraint.
In وَتَحُجَّ الْبَيْتَ إِنِ اسْتَطَعْتَ إِلَيْهِ سَبِيلًا, Hajj is explicitly tied to ability. إِنْ introduces a condition, اسْتَطَعْتَ means “you are able,” and سَبِيلًا indicates access or means to reach the House.
Detailed legal qualifications for ability belong in later fiqh study. The beginner's point is that the text itself includes a condition and must not be read as though every duty were unconditional in every circumstance.