I want a small word, if possible. Words from other languages or old English will also suffice. Can someone help me with this?
Prudent is explicitly about planning ahead:
Acting with or showing care and thought for the future. ‘no prudent money manager would authorize a loan without first knowing its purpose’
Late Middle English: from Old French, or from Latin prudent-, contraction of provident- ‘foreseeing, attending to’ (see provident).
Provident is even more related to acting ahead, but refers less to being careful:
Making or indicative of timely preparation for the future. ‘she had learned to be provident’
Circumspect could also do.
adv. With great care or delicacy; cautiously. adj. Cautious; careful: with a gingerly step.
You must step gingerly if you want a risk-free life.