Very few people in the northern parts of India know about Lord Muruga. They might have heard Lord Shiva and Parvati Devi have another son besides Lord Ganesh.
Lord Muruga is known as the Deva Senapathy or the leader of the divine army. He was born from the fire that emanated from the third eye of Lord Shiva. Demons who wanted to kill him were after him. So, he was escorted to the star cluster - the Pleiades. When he was ready, he led the army of the gods against the demons and defeated them.
Temples dedicated to Lord Muruga are there in most parts of south India. Invaders who raided the north of India more frequently might have destroyed Muruga temples.
The six most important temples dedicated to Lord Muruga are located in Tamil Nadu. The six main temples are located in Thiruparankundram, Tiruchendur, Palani, Swamimalai, Tiruttani, and Pazhamudircholai. I have visited Palani and Tiruchendur. That was a long time ago although I did visit Palani temple recently.
Lord Muruga as I mentioned earlier is a warrior. He will help conquer your enemies. So, praying to him helps you overcome any difficulties caused by people who are against you.
How to pray?
The easiest way to pray in this 'kali Yuga' is to just chant God's name.
There are famous mantras to pray to get Lord Muruga's blessings. All are available online and one needs to just play it on YouTube and hear it. If you can, learning it also helps but those who are not familiar with the Tamil language would find it difficult.
The mantras are Skanda Shashti Kavacham, Vel Maaral, Subramanya Bhujangam(sanskrit). There are many more.
Om Saravana Bhava is the simplest mantra and can be chanted by anyone who has devotion. Remember that one has to bathe, wear clean clothes, and pray with faith to receive blessings. Also, it is better to learn how to chant properly before doing so and there are various online channels for it.
Lord Muruga is often referred to as the father of Tamil and the Tamil people are always devoted to him. Do visit the temples of Tamil Nadu when you have time.
If you like to read - https://greenmesg.org/stotras/murugan/subramanya_bhujangam.php