When I’m driving under 20 mph then try to accelerate, the car will not change speed for like 5 seconds even when i push down on the pedal, then it will kick it up a notch and start accelerating out of no where.

Also if I keep the pedal at the same position, the car will eventually lose its velocity.

What is going on here? I definitely can’t fix it myself but I don’t want to walk into a shop and have someone tell me 10 things that are wrong with my car that are linked to this problem and I have no way to tell if they’re lying or not.

If y’all could narrow it down to like 4-5 issues that’d be great. Driving a 2015 madza cx9, and it’s been sitting for a couple months.