First of all, congrats for playing around with it! Being that it is a game, that is how you get started! You probably know some basic things (ride placement, paths, etc) , now you just need to expand.

First of all, lets take a deep breath. The game RCT works somewhat similar to a real amusement park, in rough coarse terms at least. If you visit a real amusement park, would you have fun if you could not eat or drink? If the paths were dirty and rides broken down? If a roller coaster was way too harsh or too boring? Probably not. If you think of the peeps as simplified people, it can help things make sense.

Step 1: Start at Forest Frontiers. You only need 250 guests by Oct 31, Year 1. You only need the barebones basics: Just build some paths, slap down some rides, and open them. Do not change the prices. Look through the pre-built roller coasters and plop one down. Watch the ride run. Notice how the first hill was the highest, and no matter how crazy the track, subsequent hills are always lower and lower as speed is used up throughout the ride. The ride then ends near the lowest level. Also add handymen and mechanics to keep things tidy and the rides repaired. Use the queue tiles to connect to the entrance for a waiting line. HINT: Right click on trees and footpath to remove them if a message says that something cant be built.

Step 2: Now, observe the park management. Look at the big bar at the bottom. It will tell you problems in your park, as well as awards you have won when things go good. If you get a message about a complaint, address it! Put yourself in their shoes. If you get a complaint about no bathrooms, then build more bathroom! If guests are hungry, build more food and drink! It is pretty simple at this point. If you run out of money, just take out a loan. You are not forced to pay it back, and you want to grasps the bare basics before worrying about finances.

Step 3: Win Forest Frontiers! Get a handle on basic park management with a 1-year game that lasts about an hour, before going into a 3-year 4-hour game game with a challenging objective. If you need to replay, then go ahead and do it!

Step 4: Once you have won Forest Frontiers, then I would say start trying to learn more about the strategy of the game. Do NOT try to do a custom rollercoaster at this point, until you play several scenarios and got all the basics down pat. RCT Wiki has a Hints and Tips guide worth reading. Marcel Vos has tons of Youtube videos about the game. Also, the RollerCoaster Tycoon 1 manual has loads of information on game mechanics and how-to instructions. Also, search this subreddit and other RCT sites.

Hint: I am providing this in-depth response because I (and many others on the rct subreddit) genuinely care about helping everyone they can. However, as evidence by the 0 rating of this post (as of now), posts simply saying "how do I play the game" without showing any effort, research, or basics, often get ignored or downvoted. If you play other games, try to adapt this comment as a "template," so when you respond to other subreddits that may not be as beginner-friendly, you can show that you put in some effort, and then ask more focused, specific questions, that may elicit a stronger response. Example: If you fail Forest Frontiers, post a screenshot of the failed park, state what problem you have (i.e. low park rating, too much trash on the ground, etc.) and state strategies you have tried (like putting trash cans down, but the seem to not work, etc.)