It depends on the type of property you are purchasing.
For a single family home, duplex, triplex or quad-plex, or townhome that is not zoned as a condominium - with no homeowners association - you would use the “One to Four Family Residential Contract (Resale)” document.
For one of the above w/ an HOA (most condos, townhomes and newer residential subdivisions have an HOA), you would use the same form plus the “Addendum for Property Subject to Mandatory Membership in an Owners’ Association” document.
For a condominium, you would use the “Residential Condominium Contract (Resale)” document (no separate HOA document is required).
Mobile homes, strip malls, raw land, multifamily properties above 4 units, car washes and “other” forms of real estate would use different contracts than above…but I bet you won’t mess with those properties in the beginning.
I fill those forms out myself when no real estate agent is involved. If the seller has an agent involved, I talk with the agent and tell them I am fine with them doing “dual representation” - which they tend to like as they get a bigger commission - and let them do all the paperwork for me, but I do still review the contract. Note: the seller pays the buyer’s agent commission.
Be careful when filling out these contracts - or any contracts for that matter - as they are legal agreements and you can get sued if you screw something up or default on an agreement. So take the time to learn & understand them. It’s not that hard.
If you have a very large chunk of money at stake, albeit cash or credit, OR if you are dealing with a chunk of money that could affect your ability to put food on the table, OR if you are doing any form of non-traditional purchasing (buying a short sale or foreclosure home, buying a house with the intention of assigning the contract to someone else before the property is closed on, etc) - don’t even think about doing your first or second contract on your own - talk with a title company, lawyer or real estate agent to make sure it’s done right.