Your Film
Regular ISO 400 print films are great for portraiture.
For professional grade travel pictures I have used Fujichrome Velvia, Provia 100 and 400, Kodachrome 64 and 25, and Elite with great satisfaction. Generally I use Provia now.
Kodachrome 25 handles dark and light contrast very well and is great for forest photography, with a tripod.
I suggest the following ideas.
Replace old film.
Use print film for practising your techniques, memento photos, social occasions, arty stuff and portraits (black and white, sepia and color).
Use slide film for professional photojournalism.
Try the film marked Professional, it is very good. Think of each frame as an exquisite little canvas awaiting its own unique miraculous imprint of God's good light!