This site is a great place to start: aussiebushwalking.com

Here is the link to their sections on the Brisbane Forest park D'Aguilar National Park, which has some great walks.

Each trail listed has photos and an elevation map.

Here is a good breakdown of the Trails on Mount Coot-tha: Best Trails in Mount Coot-tha Reserve from another good walking info site.

mt ngungun in the glass house mountains is a great beginner walk. It's short but rewarding.

I often just go to to the top of Mt glorious for a weekend walk, a really lovely walk is the rainforest loop from the Maiala day-use area

here's a page that has a map of that area and others. try the hike just over the road to the western window too, also very pretty and easy going. https://parks.des.qld.gov.au/parks/daguilar/maps-resources

Have a look at the AllTrails app or website . It's great, and trends to have community recommendations.

Mt Gravatt / Toohey Forest is a quick, beginner friendly option if you're local.

White Rock near Ipswich is pretty easy.

There’s a few around Springbrook of varying lengths including one through Natural Bridge that is quite pretty.