Can I burn incense and worship Buddha once a week?

Of course you can. You can go every day.

Burning incense and praying for blessings mainly means offering sacrifices to Buddhas and Bodhisattvas to pray for blessings. Whether it is useful or not depends on whether your blessing is enough. If so, the wishes of Buddha and Bodhisattva will come true soon. There is merit in worshipping Buddha, and there is merit in worshipping once. There is some truth in people's joking that they don't study hard at ordinary times and come to worship Buddha. Buddha should always worship, so the accumulated blessings and merits are enough, and praying for something is very spiritual. Because it is inconvenient to go to the temple to worship Buddha, it would be better if someone invited Buddha to go home and burn incense every day.