Can a non-Hindu follow these practices?

yes — prayer, mantra, meditation, the Gītā and festivals are open to anyone who approaches them with respect.

Hindu dharma has never had a single entry gate or a requirement to give up one's background. People of many faiths and none read the Gītā, practise yoga and meditation, chant mantras, celebrate Dīpāvalī and Holī, and visit temples. Most temples, ISKCON centres and āśramas warmly welcome sincere visitors.

A few points of respect help. Learn the meaning of what you chant and the customs of the place you visit. Some temples, such as the Jagannāth temple at Purī and the Guruvāyūr temple in Kerala, admit only Hindus into the inner shrine; honour that rule as their tradition, and enjoy darśana where it is allowed. Certain initiations (dīkṣā) and rites within particular sampradāyas have their own conditions, which a teacher will explain.

The tradition says God looks at the heart. Come with humility and curiosity, and you will find the door open.

Source: common practice · Some temples admit only Hindus inside

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