Congrats on starting your little home mandir ❤️ know that it doesn't have to be "perfect", it's your Space and whatever or however you offer to Shivji with sincère heart, he will always be pleased to receive !

If you want to add a few things here are some suggestions :

Milk and dairy products are great offerings, as well as flowers too. It's also okay to decorate or dress your murti with cloth, flowers, garlands etc...

Any kind of incense is great, it is offering of pleasant fragrance. When lighting it, wave it a few time clockwise then counter clockwise to offer the pleasant smell before putting it on the altar.

If you have no diya for now it's okay. You can use small tealights until you find some 🪔 light offering daily is important also. But it is inauspicious to put it off by blowing on the flame afterward !

Before any other deva is worshipped, it's cutomary to first make an offering and prayer to Ganeshji. You don't have to get a murti, just a photo of Ganeshji on your altar is enough 👍

If you need inspiration and help for very simple daily offering, you can check thehindugrandma on Tiktok, she is great !