While it's technically an option, the first thing you need to do is get those problems looked at by a mechanic. You need to know exactly what the problem is, since those indicator lights don't tell you anything on their own. You could exercise the option of ignoring the problem, but that could turn out very badly.
Option one is to look at the purchase & sale agreement, especially the part about any warranties or conditions. Option two is to read those warranties and conditions carefully. If the vehicle was sold with conditions / warranty, and if the conditions / warranty cover your exact problem(s), the seller will pay for the repairs. If the problem is not covered by your agreement, the repair costs are on you.
If you purchased the vehicle as is, the seller has no responsibilities for the vehicle whatsoever.