There’s lots of lovely interiors instagrammers that do great content and have lovely homes (some rented, some on a budget, some on bigger budgets).
The trick is to find your style. Do you like period, mid century, modern, industrial, boho? Etc. you’ll find you gravitate to one or two.
Generally go with 70/20/10 rule in terms of colour. 70% main colour, 20% second colour, the rest on a small splash of bright or whatever.
Example, neutral walls, perhaps blue sofa, or rug, bright orange cushions. For example.
Lots of great insta people to get ideas from, search out some interiors hashtags - you’ll see loooads.